Which Best Describes a Role of L-Type Ca²⁺ Channels in Cardiac

Which best describes a role of L-type Ca²⁺ channels in cardiac muscle cells?

A) They function exactly the same in cardiac muscle cells as they do in skeletal muscle.
B) They are directly responsible for making cardiac muscle fatigue-resistant.
C) They are responsible for preventing tetanic contractions.
D) They cause the absolute refractory period to be very brief.
E) They act as non-conducting voltage sensors that mediate excitation-contraction coupling.