Choose the correct option from below mentioned change in voice of the given…

Concept:

To change an active sentence into the passive voice, the object of the active sentence becomes the new subject, the verb changes to the form "be + past participle", and the original subject moves into a "by ..." phrase. The tense of the original verb must be kept unchanged. For a verb in the present continuous (am/is/are + verb-ing), the passive is "am/is/are + being + past participle". With a phrasal verb such as "look after", the particle ("after") stays attached to the verb in the passive.

Application:

1. Identify the parts of the active sentence: subject = "The nurse", verb = "is looking after" (present continuous of the phrasal verb "look after"), object = "this little girl".

2. Make the object the new subject, keeping its words: "This little girl ...".

3. Build the present continuous passive verb: is + being + looked after → "is being looked after", keeping the particle "after" with the verb.

4. Add the agent with "by", keeping the original determiner: "by the nurse".

5. Textbook passive: This little girl is being looked after by the nurse.

Choosing the best option:

The closest choice is "This little girl is being looked after by this nurse." It is the only option that does both load-bearing things correctly: it keeps "This little girl" as the subject AND keeps the present continuous passive verb "is being looked after". Its only flaw is the agent determiner — it says "by this nurse" where the original determiner gives "by the nurse". Because the other choices fail on a more basic rule (voice or tense), this remains the intended answer.

Why the others are rejected:

• "It is the nurse who is looking after this little girl." stays in the active voice (an emphasis/cleft construction), so no voice change has been made.

• "This little girl is looked after by the nurse." switches to the simple present passive and so changes the tense of the original present continuous — a voice change must not alter the tense.

• "The little girl is being looked after by this nurse." alters the subject noun phrase, turning "this little girl" into "the little girl" (and also "the nurse" into "this nurse").