Choose the arrangement that lists the events in the order they occur during muscle contraction. (1) Calcium ions combine with tropomyosin. (2) Calcium ions combine with troponin. (3) Tropomyosin pulls away from actin. (4) Troponin pulls away from actin. (5) Tropomyosin pulls away from myosin. (6) Troponin pulls away from myosin. (7) Myosin binds to actin.