Which statement is true about body temperature?
a. the nervous system is a source of heat for the body.
b. muscles generate heat through activity.
c. sweat increases the body's temperature.
d. essential life functions can be carried out at any temperature.

muscles generate heat through activity.

Explanation:

During body activities (such as walking, running, eating) the muscles of the body are contracting and relaxing, and utilizing energy compounds like glucose to produce ATP to drive these activities.

Thus, heat energy is generated in the muscles and the body temperature rises followed by sweat release from the skin

answer; ////increased water pollution; ///////////////////////