Work Step by Step
Option a. is incorrect. The sarcoplasm is the cytoplasm of a muscle fiber.. Option b. is incorrect. The sarcoplasmic reticulum is the smooth endoplasmic reticulum of a muscle fiber. It stores calcium ions. Option d. is incorrect. The sarcomere is a vertical division of the myofibril. Option c. is correct. The plasma membrane of a muscle fiber is called the sarcolemma.