The addictive ingredient of cigarette smoking is​

A) ​nicotine.
B) ​its good taste.
C) ​the approval of peers.
D) ​the aroma of the smoke.

Nicotine is the addictive ingredient in cigarette smoking. It is a highly addictive substance that acts as a stimulant, increasing the levels of dopamine and other neurotransmitters in the brain. This creates a sensation of pleasure and relaxation, which can lead to addiction.