During the propagation of the excitation wave along the sarcolemma, the action potentials travel down the

During the propagation of the excitation wave along the sarcolemma, the action potentials travel down the transverse (T) tubules. and thus stimulates the intracellular release of the calcium ions. Propagation of an action potential along the sarcolemma is the excitation portion of excitation coupling and must be coupled to the release of calcium ions for contraction. 

The answer is c. they had seedshope this

He used pea plants to study the patterns of heredity.