Define the terms skeletal muscle fiber, motor unit, skeletal muscle twitch, electrical stimulus, and latent period.

Skeletal muscle fiber is a muscular tissue that is attached to the skeletal system. the skeletal muscle fibers are striated muscles i.e have striations in their structure. The skeletal muscle fibers are voluntary muscles i.e they can be controlled.

Motor unit is a composed of a motor nerve cell attached to a muscle fiber with its axon terminals. Motor nerve cells or neurons are the types of neurons that send impulses from the central nervous system to the responding organ. The muscle fiber may be attached to many neurons not only one neuron. Collectively, all the neurons attached to the same muscle fiber are called motor pool.

A skeletal muscle twitch is the contraction of a muscle fiber in response to the minimum stimulation.

The electrical stimulus is the stimulation of a skeletal muscle fiber by using external electrical impulses. The electrical stimulus is important in many sporting and medical situations.

A latent period is a period between applying a stimulus to a muscle fiber and the response of this muscle fiber by contraction. 

The answer is option b.