Future Continuous: This tense is used to describe actions that will be ongoing or in progress at a specific time in the future. It is formed using the future tense of the verb "to be" (will be) followed by the present participle of the main verb (-ing form). For example: "I will be studying tomorrow evening." In the given sentence "She will be arriving tomorrow to meet her husband," the tense is future continuous because it describes an action (arriving) that will be happening at a specific future time (tomorrow).

Present Continuous: This tense is used to describe actions that are currently happening at the time of speaking. It is formed using the present tense of the verb "to be" (am, is, are) followed by the present participle of the main verb (-ing form). For example: "I am reading a book." In the given sentence, the action of arriving is not happening currently but is anticipated to happen in the future, so the present continuous tense is not applicable.

Past Indefinite: "Past Indefinite" is not a recognized tense in English grammar. The term "Indefinite" does not refer to a specific tense. It is possible that "Past Indefinite" refers to the simple past tense, which is used to describe actions that occurred and were completed at a specific time in the past. However, this tense is not applicable in the given sentence because it does not describe a past event.

Past Continuous: This tense is used to describe actions that were ongoing at a specific time in the past. It is formed using the past tense of the verb "to be" (was, were) followed by the present participle of the main verb (-ing form). For example: "I was reading a book when the phone rang." In the given sentence, the action of arriving is not happening in the past but is anticipated to happen in the future, so the past continuous tense is not applicable.

Therefore, the correct tense used in the given sentence is Future Continuous.

Hence option A is the correct answer .

Present Continuous: This tense is used to describe actions that are currently happening at the time of speaking. It is formed using the present tense of the verb "to be" (am, is, are) followed by the present participle of the main verb (-ing form). For example: "I am eating dinner." In the given sentence "Probably, it will be raining when you reach Bhopal," the tense is not present continuous because it refers to a future event (raining when you reach Bhopal) rather than something happening currently.

Past Indefinite: "Past Indefinite" is not a recognized tense in English grammar. The term "Indefinite" does not refer to a specific tense. It is possible that "Past Indefinite" refers to the simple past tense, which is used to describe actions that occurred and were completed at a specific time in the past. However, this tense is not applicable in the given sentence because it does not describe a past event.

Future Continuous: This tense is used to describe actions that will be ongoing at a specific future time. It is formed using the future tense of the verb "to be" (will be) followed by the present participle of the main verb (-ing form). For example: "I will be studying tomorrow evening." In the given sentence, "Probably, it will be raining when you reach Bhopal," the tense is future continuous because it describes an action (raining) that will be happening at a specific future time (when you reach Bhopal).

Past Continuous: This tense is used to describe actions that were ongoing at a specific time in the past. It is formed using the past tense of the verb "to be" (was, were) followed by the present participle of the main verb (-ing form). For example: "It was raining when I left home yesterday." In the given sentence, the tense is not past continuous because it refers to a future event (raining when you reach Bhopal) rather than something happening in the past.

Therefore, the correct tense used in the given sentence is Future Continuous.

Hence option C is the correct answer .