The Removal of Calcium Ions from the Cytosol of Skeletal

The removal of calcium ions from the cytosol of skeletal muscle causes

A) the myosin binding sites on actin to be uncovered by tropomyosin.
B) tropomyosin to change conformation and thereby move troponin molecules over cross-bridge binding sites.
C) troponin to change conformation and thereby expose cross-bridge binding sites.
D) the myosin binding sites on actin to be covered by tropomyosin.
E) None of the choices is correct.