skeletal muscle tension: which of the following can result in a change in the amount of tension developed in an individual skeletal muscle fiber? a) increasing the frequency of action potentials generated by the muscle fiber during contraction b) increasing in the number of motor units activated during contraction. c) extending the muscle fiber to its maximum length prior to contraction d) both a) and b) are correct, and c) is incorrect e) a), b) and c) are all correct