The given sentence is in active voice. Change the voice of the sentence. Select the correct option from the sentences given in options.

Vasant has delivered the speech.

The speech has been delivered by Vasant.

The correct passive form of the given sentence is The speech has been delivered by Vasant.

The active voice of the sentence is Vasant has delivered the speech. This sentence is in the present perfect tense, which is used to describe an action that has happened in the past but 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 "Vasant" and the main verb is "deliver." The past participle of "deliver" is "delivered." So, the passive form of the sentence is The speech has been delivered by Vasant.

The other options are incorrect because:

• Vasant delivers the speech on time. is in the active voice.
• The speech was delivered by Vasant. is in the simple past tense, while the original sentence is in the present perfect tense.
• The speech was timely delivered by Vasant. is grammatically incorrect. The adverb "timely" modifies the verb "delivered," but the verb "delivered" is in the past participle form, which does not take adverbs.