Sentence improvement: remove the double negative and keep the advised infinitive form Original sentence: "Because of his ill health, the doctor has advised him not to refrain from smoking." Select the correction that produces a clear, affirmative instruction.

Given data

• Main verb: "has advised him".
• Current complement: "not to refrain from smoking" (double negative → advises him to smoke unintentionally).

Concept/Approach
After advise, use an infinitive with to: "advise someone to do something". To tell him not to smoke, we must say "advise him to refrain from smoking" (one clear negative).

Option analysis
to refrain from — correct infinitive complement; removes the double negative. ✅to not refrain from — retains double negative, reversing the intended meaning.to resort to — wrong verb; changes meaning.to be refrained from — passive/awkward; unidiomatic after advise.No correction required — incorrect because the original has faulty logic.

Final Answer
"The doctor has advised him to refrain from smoking."