Sensitization usually occurs:

A) as a result of cellular tolerance.
B) as a result of metabolic tolerance.
C) in a new environment.
D) in a familiar environment.

Sensitization

The method wherein continuous exposure to an external factor progressively increases the intensity of a reaction.

Cellular Tolerance

A phenomenon occurring when cells decrease their responsiveness to a substance after repeated exposure.

Environmental

Relating to the natural and built surroundings in which organisms live, including all living and non-living things.