Skeletal muscle
A. The myosin head is activated (energized) by the conversion of GTP (that is bound to myosin) to GDP and Pi (that are bound to myosin).
B. Detachment of the myosin head from its actin binding site always occurs during rigor mortis.
C. The binding of ATP to troponin occurs when the myosin head is not attached to the troponin receptor site.