Experiments Have Shown That Following a Series of Voluntary Contractions

Experiments have shown that following a series of voluntary contractions to produce skeletal muscle fatigue,electrical stimulation of the "fatigued" muscle group results in an increase in the maximal voluntary force production.This experiment suggests that:

A) exercise-induced muscle fatigue results from peripheral factors located within the muscle.
B) exercise-induced muscle fatigue results from peripheral factors located at the neuromuscular junction.
C) the upper limit of voluntary strength is psychologically set and that the central nervous system can limit performance.
D) None of the above answers are correct