Which of the following statements regarding muscle fiber types is true: a. the number of ft and st fibers does not vary from one individual to another. b. most skeletal muscles contain both ft and st fibers. c. individual performance differences cannot be attributed to the varying percentages of the muscle fiber types. d. the number of ft and st fibers varies from one muscle to another.

Option B

Explanation:

People generally have two types of skeletal muscles fibers: slow twitch and fast twitch. Slow twitch muscles functions by providing long endurance feats. Example for distance running.

The slow twitch muscles fatigue helps in providing fatigue faster but it is used in the powerful busts of movements example: sprinting.

Most of the body's skeletal system contains both types of muscles: soft twitch and fast twitch.

its temperature is increasing. this causes molecular vibrations to increase.