Kamal is singing a song.

Correct option is A

For present continuous tense in passive voice, use "is being + past participle." The subject and object have switched places.

Information Booster

Active: Subject + is/am/are + verb-ing + object.
Passive: Object + is/am/are + being + past participle + by + subject.
Active: Kamal is singing a song.
Passive: A song is being sung by Kamal.
This construction preserves the sense of action happening right now.
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Additional Knowledge

Option 2 is present perfect tense (“has sung”), not present continuous.

Option 3 is present perfect continuous, which does not match the original tense.

Option 4 is simple present passive (“is sung”), which does not reflect the ongoing action.