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

She is looking after the old ladies with great affection.

The old ladies are being looked after with great affection.

The correct passive voice form of the sentence "She is looking after the old ladies with great affection" is The old ladies are being looked after with great affection.

The active voice of the sentence is "She is looking after the old ladies with great affection." This sentence is in the present progressive tense, which is used to describe an action that is happening now but is not finished. 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 "she" and the main verb is "look after." The past participle of "look after" is "looked after." So, the passive form of the sentence is "The old ladies are being looked after with great affection."

The other options are incorrect because:

• She is looked after with great affection by the old ladies." This sentence is in the passive voice, but the subject of the sentence is "she," which is not the one being acted upon.
• The old ladies were looked after with great affection." This sentence is in the past tense, but the action of looking after the old ladies is still happening.
• The old ladies are looked after with great affection." This sentence is in the present tense, but the action of looking after the old ladies is not happening now.