Which of the Following Statements Is TRUE Regarding Skeletal Muscle

Which of the following statements is TRUE regarding skeletal muscle contraction?

A) During the excitation phase, Ca²⁺ enters the motor neuron through chemically gated channels and causes exocytosis of acetylcholine into the synaptic cleft.
B) An action potential is generated and propagated along the sarcolemma due to K⁺ influx through voltage gated channels.
C) The myosin head binds to the actin receptor region once it has hydrolyzed ATP and the regulatory proteins (Troponin and tropomyosin) have been "pulled out of the way."
D) The powerstroke occurs immediately after the myosin head has hydrolyzed the ATP molecule.
E) ATP is necessary for coupling to occur, however, Ca²⁺ is only used during maximal force contractions.