The drugs used by weight-conscious people to reduce appetite and increase alertness are

Which factor is responsible for liver cirrhosis?

Which of the following effects is $NOT$ caused by smoking?

Physical and mental dependency on any specific drug is known as

For Assertion $A$ and Reason $R$:
Assertion $A$: Smoking increases blood pressure and heart rate.
Reason $R$: Nicotine stimulates the adrenal gland.

Nicotine acts as a stimulant because it mimics the effect of ......... .