The hydrosphere 'water', and is the combined mass of water found on, under, and above the surface of a planet, minor planet, or natural satellite. Although Earth's hydrosphere has been around for about 4 billion years, it continues to change in shape. This is caused by seafloor spreading and continental drift, which rearranges the land and ocean.

History:

• According to Merriam Webster, the word hydrosphere was brought into English in 1887, translating the German term hydrosphäre, introduced by Eduard Suess.

Water cycle:

• The water cycle refers to the transfer of water from one state or reservoir to another.
• Reservoirs include atmospheric moisture (snow, rain and clouds), streams, oceans, rivers, lakes, groundwater, subterranean aquifers, polar ice caps and saturated soil.
• Solar energy, in the form of heat and light (insolation), and gravity cause the transfer from one state to another over periods from hours to thousands of years.
• Most evaporation comes from the oceans and is returned to the earth as snow or rain. 27 Sublimation refers to evaporation from snow and ice.
• Transpiration refers to the expiration of water through the minute pores or stomata of trees.

Recharging reservoirs:

• According to Igor A. Shiklomanov, it takes 2500 years for the complete recharge and replenishment of oceanic waters, 10,000 years for permafrost and ice, 1500 years for deep groundwater and mountainous glaciers, 17 years in lakes, and 16 days in rivers.

Human impact:

• The activities of modern humans have drastic effects on the hydrosphere.
• For instance, water diversion, human development, and pollution all affect the hydrosphere and natural processes within.
• Humans are withdrawing water from aquifers and diverting rivers at an unprecedented rate.
• The Ogallala Aquifer is used for agriculture in the United States; if the aquifer goes dry, more than $20 billion worth of food and fiber will vanish from the world's markets.
• The aquifer is being depleted so much faster than it is replenished that, eventually, the aquifer will run dry.

Hence, Option Correct is C.

Water covers most of the Earth's surface, about 71% of it. The vast majority of this water is in the form of oceans, which cover approximately 361 million square kilometers (139 million square miles) of the Earth's surface.

• Water covers most of the Earth's surface, about 71% of it. The vast majority of this water is in the form of oceans, which cover approximately 361 million square kilometers (139 million square miles) of the Earth's surface. The remaining surface area of the Earth is made up of continents and islands. The largest continents are Asia, Africa, North America, South America, Antarctica, Europe, and Australia, with a combined land area of approximately 148 million square kilometers (57 million square miles).

• Earth's surface is covered by atmosphere.
• Water covers about 70%. Land covers about 30%. But the atmosphere covers 100%.
• There is atmosphere above earth's surface.
• But if you say the whole earth then, the answer is space. Space also covers 100% of the atmospheric surface of earth.

Hence, Option Correct is D.

Historically, there are four named oceans: the Atlantic, Pacific, Indian, and Arctic. However, most countries - including the United States - now recognize the Southern (Antarctic) as the fifth ocean. The Pacific, Atlantic, and Indian are the most commonly known. The Southern Ocean is the 'newest' named ocean.

• Planet Earth, when viewed from space, has been described as a "blue marble." This is, of course, because it's covered in water. Our planet sustains life partially thanks to the 321,003,271 cubic miles (1,338,000,002 cubic kilometers) of salt water that continually circulates around and between the comparatively small bits of exposed land.

How Many Oceans Are There in the World?

• Pacific Ocean
• Atlantic Ocean
• Indian Ocean
• Southern Ocean
• Arctic Ocean

The Atlantic, Indian and Pacific freeze together around Antarctica.

How Do We Separate the World's Oceans?

• There are no real barriers between the world's oceans like there are with landmasses, mostly because bodies of water are often what we use to create geographical boundaries. Just like an island's borders are drawn by water, continents mostly use oceans to describe their boundaries. There is only one global ocean, and yet we have to make distinctions between areas, for geography's sake.
• In 1999, the National Oceanic and Atmospheric Administration (NOAA) decided that the Southern Ocean should be recognized as a separate body of water, but it took until 2021 for the IHO and the National Geographic Society to recognize it as separate from the Pacific Ocean.

The 5 Oceans of Planet Earth

• All the oceans are pretty similar — after all, they're all the same body of water. However, differences in temperature, salinity and density exist between the oceans
• . For instance, the Atlantic Ocean is slightly saltier than the Pacific, due to a dizzying number of factors, from the way the water cycle works to the effects of hydrothermal vents.

Hence, Option B is correct Answer.