Identify the synonym of the word `abstain' as used in the sentence:
"Doctors advise people to abstain from smoking.''
The word 'abstain' generally means to hold oneself back voluntarily, especially from something regarded as improper or unhealthy. In the sentence: "Doctors advise people to abstain from smoking," the intention is to suggest avoiding the activity.
Let's evaluate the options:
Hence, the correct synonym for 'abstain' in this context is 'Avoid'.

