Select the correct passive form of the given sentence.

The citizens have chosen that man as their leader.

That man has been chosen by the citizens as their leader.

The correct passive form of the given sentence is That man has been chosen by the citizens as their leader.

The active voice of the sentence is "The citizens have chosen that man as their leader." This sentence is in the present perfect tense, which is used to describe an action that has happened in the past and is still relevant to the present. The passive voice of the sentence is formed by putting the subject of the active sentence after the verb "to be" and the past participle of the main verb. In this case, the subject of the active sentence is "man" and the main verb is "choose." The past participle of "choose" is "chosen." So, the passive form of the sentence is "That man has been chosen by the citizens as their leader."

The other options are incorrect because:

• That man had been chosen by the citizens as their leader." This sentence is in the past perfect tense, which is used to describe an action that happened in the past before another action happened. However, there is no other action mentioned in the sentence.
• That man is chosen by the citizens as their leader." This sentence is in the present tense, but the action of choosing the man as a leader happened in the past.
• That man was chosen by the citizens as their leader." This sentence is in the simple past tense, but the verb is in the singular form, while the subject of the sentence is plural.