Choose the correct option to change the following sentence from Active Voice to Passive Voice:

They have postponed the concert.

The concert has been postponed by them.

The correct answer is Option (1) - The concert has been postponed by them.

In the given sentence "They have postponed the concert," the tense is present perfect tense. When changing to passive voice, the object ("the concert") becomes the subject, and the verb is adjusted to include "has been" to maintain the present perfect tense.

1. The concert has been postponed by them.

   • Correct: This accurately reflects the tense and maintains the meaning of the original sentence in passive voice.

2. The concert is postponed by them.

   • Incorrect: This changes the tense to present simple, which does not match the original sentence.

3. The concert is postponed.

   • Incorrect: This changes the tense to present simple and removes the agent ("by them"), which alters the meaning.

4. The concert may be postponed by them.

   • Incorrect: This introduces a modal ("may"), which changes the meaning of the sentence.