Active Voice : - In the active voice, the sentence's subject performs the action on the action's target.

Passive Voice : - In the passive voice, the target of the action is the main focus, and the verb acts upon the subject.

Conversion  of Passive Voice Sentence into Active Voice For Auxiliary Verbs:

Rule used to identify that the sentence is in Active Voice form with Auxiliary Verbs is:

Subject+ Modals verb + object (active)

For Example: 

•  She can cook the food.

 Here she is subject , cook  is verb and the food is object.

While converting into Passive Voice the rule will be :

Subject + modals + be + third form of verb + by + agent (passive).

In the question : -

They ought to take the examination.

The passive form of above sentence for auxiliary verb is : -

The examination ought to be taken by them. In this sentence ,subject ( they ) is converted into object (the examination) and then we use modal ought to, use be , then third form of verb (taken) ,  then use by preposition and then the remaining part is the subject ( they ) . In objective part , it gets changed into them .

Thus , the Correct Option is D , which is The examination ought to be taken by them.

Active Voice : - In the active voice, the sentence's subject performs the action on the action's target.

Passive Voice : - In the passive voice, the target of the action is the main focus, and the verb acts upon the subject.

Conversion  of Passive Voice Sentence into Active Voice For Auxiliary Verbs:

For Negative sentence:

Rule: subject + modal + not + first form of verb + object

For Example:

• He cannot drive a car.( active)

The object 'him' will change into subject and the subject 'he' will change into object and the verb first form will be used according to the  rule.

While converting into Active Voice the rule will be :

Rule: subject + modal + not + be + third form of the verb + by + object

In the question : -

You ought not to clean this house .

The passive form of above sentence for auxiliary verb is : -

This room ought not to be cleaned by you . In this sentence ,subject ( you ) is converted into object ( this room ) and then we use modal ought to, then use not , use be , then third form of verb (cleaned ) ,  then use by preposition and then the remaining part is the subject ( you ) .

Thus , the Correct Option is C , which is This room ought not to be cleaned by you .

Active Voice : - In the active voice, the sentence's subject performs the action on the action's target.

Passive Voice : - In the passive voice, the target of the action is the main focus, and the verb acts upon the subject.

Conversion  of Passive Voice Sentence into Active Voice For Auxiliary Verbs:

Rule used to identify that the sentence is in Active Voice form with Auxiliary Verbs is:

Subject+ Modals verb + object (active)

For Example: 

•  She can cook the food.

 Here she is subject , cook  is verb and the food is object.

While converting into Passive Voice the rule will be :

Subject + modals + be + third form of verb + by + agent (passive).

In the question : -

1. She might finish the task .

The passive form of above sentence for auxiliary verb is : -

The task might be finished by her . In this sentence ,subject ( she ) is converted into object ( the task ) and then we use modal might , use be , then third form of verb (finished) ,  then use by preposition and then the remaining part is the subject ( she ) . In objective part , it gets changed into her .

2. He might win a prize .

The passive form of above sentence for auxiliary verb is : -

A prize might be won by him . In this sentence ,subject ( he ) is converted into object ( a prize) and then we use modal might , use be , then third form of verb (won ) ,  then use by preposition and then the remaining part is the subject ( he ) . In objective part , it gets changed into him .

Thus , the Correct Option is A , which is 1. The task might be finished by her . 2. A prize might be won by him .