The correct answer is option 3 i.e. A flower had been plucked by Rahul from the garden.

Past Perfect Tense

Active voice- Subject + had + past participle + object + other words.

Passive voice-  Object + had + been + past participle + by + subject + other words.

The chosen option follows this structure hence, it will be the correct answer.

The correct answer is option 4 i.e. The tense silence was broken by her.

Simple Past Tense:-

Active voice- Subject + v2 + object + other words.

Passive voice-  Object + was/were + v3 + by + subject + other words.

The chosen option follows this structure hence, it will be the correct answer.

The correct answer is option 2 i.e. Let the work be done at once.

Imperative sentences:

Active: Verb + object

Passive: Let + object + be + past participle

The chosen option follows this structure hence, it will be the correct answer.

The correct answer is option 3 i.e. By whom is this mess being created?

Active: Who + is + v-ing + object...?

Passive: By whom + is/are/am + object + being + verb (IIIrd form).....?

The chosen option follows this structure hence, it will be the correct answer.

The correct answer is option 3 i.e. Your suitcase will be looked after at the night.

Simple Future Tense:

Active voice- Subject + will + v1 + object + other words.

Passive voice-  Object + will be + v3 + by + subject + other words.

The chosen option follows this structure hence, it will be the correct answer.

The correct answer is option 3 i.e. At least two languages should be learnt by students.

Modal Verbs:

Active voice- Subject + modals + v1 + object + other words.

Passive voice-  Object + modals + be + past participle + by + subject + other words.

The chosen option follows this structure hence, it will be the correct answer.

The correct answer is option 3 i.e. An act has been prepared by them for the annual function.

Given sentence: They have been preparing an act for the annual function.

Correct passive form: An act has been prepared by them for the annual function.

Reason:

• The original sentence is in present perfect continuous tense.

• When converting to passive voice, it is appropriate to use present perfect tense instead of continuous for grammatical correctness.

• Subject ('They') becomes the agent ('by them'), and the object ('an act') becomes the new subject.

Final Sentence: An act has been prepared by them for the annual function.

Hence, the chosen option will be correct.

The correct answer is option 4 i.e. Was my advice understood by you?

Active voice- Did + subject + v1 + object + other words?

Passive voice- Was/were + object + v3 + by + subject + other words?

As the chosen option follows this structure it will be the correct answer.

The correct answer is option 1 i.e. We saw her dancing at the birthday party.

Simple Past Tense:-

Passive voice- Subject + was/were + v3 + by + object + other words.

Active voice- Subject + v2 + object + other words.

When the object is silent in the passive voice, "we" or "they" can be considered as subject in the active voice.

As the chosen option follows this structure it will be the correct answer.

The correct answer is option 3 i.e. The new ship will be launched next week.

Simple Future Tense:

Active voice - Subject + will + v1 + object + other words.

Passive voice- Object + will + be + v3 + by + subject + other words.

As the chosen option follows this structure it will be the correct answer.