Which of the Following Statements Is True of the Mechanism

Which of the following statements is true of the mechanism of action of direct-acting skeletal muscle relaxants?

A) Direct-acting skeletal muscle relaxants facilitate skeletal muscle fiber contraction.
B) Direct-acting skeletal muscle relaxants interact with special receptors in the sarcoplasmic reticulum to block the release of calcium ions.
C) Direct-acting skeletal muscle relaxants directly affect the nicotinic-muscle receptors.
D) Direct-acting skeletal muscle relaxants act within the central nervous system to produce skeletal muscle relaxation.