Given these events: Choose the arrangement that lists the events in the order they occur following a single stimulation of a skeletal muscle fiber. (1) The sarcoplasmic reticulum releases Ca2+. (2) The sarcoplasmic reticulum takes up Ca2+. (3) Calcium ions diffuse into the sarcoplasm. (4) An action potential moves down the T tubule. (5) The sarcomere shortens. (6) The muscle relaxes.