Which Statement About Skeletal Muscle Contraction Is Not True

Which statement about skeletal muscle contraction is not true?

A) A single action potential at the neuromuscular junction is sufficient to cause a muscle to twitch.
B) Once maximum muscle tension is achieved, no ATP is required to maintain that level of tension.
C) An action potential in the muscle cell activates contraction by releasing Ca²⁺ into the sarcoplasm.
D) Summation of twitches leads to a graded increase in the tension that can be generated by a single muscle fiber.
E) The tension generated by a muscle can be varied by controlling how many of its motor units are active.