Answer : 1. "cut down"
Explanation :

In the given sentence, "Pintu has been advised to reduce smoking by his family doctor," the word "advised" is used correctly and does not require substitution.

Explanation:

Pintu has been advised: This part of the sentence indicates that someone (in this case, Pintu's family doctor) gave advice or recommendations to Pintu. "Advised" is the past participle form of the verb "advise," used in passive voice.

to reduce smoking: This infinitive phrase clarifies the advice given to Pintu. He has been advised to reduce his smoking habit, meaning he should smoke less or quit smoking altogether.

by his family doctor: This prepositional phrase tells us who gave the advice, specifying that it was Pintu's family doctor. The preposition "by" indicates the source or origin of the advice.

The sentence conveys the idea that Pintu received advice from his family doctor to cut down on smoking, and the structure of the sentence is correct and clear.