Which Is a TRUE Statement About Excitation-Contraction Coupling

Multiple Choice

Which is a TRUE statement about excitation-contraction coupling?

A) In skeletal muscle cells,it requires the influx of extracellular calcium ion.
B) In smooth muscle cells,it must be preceded by an action potential in the cell membrane.
C) In all kinds of muscle it requires the entry of calcium from the extracellular fluid.
D) Calcium-induced calcium-release plays a role in cardiac muscle cells,as well as in some smooth muscle cells.
E) In skeletal muscle cells,EC coupling begins when an action potential propagates along the sarcoplasmic reticulum membrane.