The ability of body organs and systems to put forth extra effort in times of stress is called

A) homeostasis.
B) reserve capacity.
C) senescence.
D) None of these; no such ability exists.

Reserve Capacity

The extra amount of functional capability that an organism or system can draw upon when needed.

Homeostasis

The biological process by which living organisms maintain a stable internal environment despite changes in the external environment.

Senescence

The biological process of aging, characterized by the gradual decline in physiological functions and increased vulnerability to diseases.