Select the option that expresses the given sentence in passive voice.

The man was repairing the tyres of his car.

The tyres of his car were being repaired by the man.

The correct passive voice of the given sentence is The tyres of his car were being repaired by the man.

The active voice of the sentence is The man was repairing the tyres of his car. This sentence is in the past continuous tense, which is used to describe an action that was happening in the past and was continuing at a certain point in time. The passive voice of the sentence is formed by putting the subject of the active sentence after the verb "to be" and the present participle of the main verb. In this case, the subject of the active sentence is "the man" and the main verb is "repair." The past participle of "repair" is "repaired." So, the passive form of the sentence is The tyres of his car were being repaired by the man.

The other options are incorrect because:

• The tyres of his car was being repaired by the man. is grammatically incorrect. The subject of the passive sentence is plural, so the verb "was" should be "were."
• The tyres of his car were been repaired by the man. is grammatically incorrect. The past participle of the verb "repair" is "repaired," not "been repaired."
• The tyres of his car were repaired by the man. is in the simple past tense, while the original sentence is in the past continuous tense.