The two most important symptoms of physical dependence on a drug are:

A) tolerance and failing to attend important occasions due substance use.
B) withdrawal and substance abuse.
C) tolerance and withdrawal.
D) intolerance of most anything and withdrawal.

Physical Dependence

A physiological state of adaptation to a substance, characterized by the emergence of withdrawal symptoms when the substance is not taken.

Withdrawal

The process of reducing or eliminating the use of a substance to which one has become dependent, often resulting in uncomfortable or harmful physical or psychological effects.

Tolerance

The process by which an organism becomes less responsive to a substance or stimulus after repeated exposure.