Which of the following statements are correct regarding skeletal muscle?
A) Muscle bundles are held together by collagenous connective tissue layer called fascicle.
B) Sarcoplasmic reticulum of muscle fibre is a store house of calcium ions.
C) Striated appearance of skeletal muscle fibres is due to distribution pattern of actin and myosin proteins.
D) M line is considered as a functional unit of contraction called sarcomere.
Choose the most appropriate answer from the options given below.