Put the chemical formulas in the order they would occur in one cross-bridge cycle, beginning with the resting state at the top.
1.ATP + H2O → ADP + Pi (inorganic phosphate)
2.ATP + calcium → ADP + Pi + calcium-bound myosin
3.ADP + Pi + calcium-bound myosin → ATP + calcium + myosin head in high-energy state
4.ATP + calcium + myosin head in high-energy state → ADP + Pi + calcium-bound myosin
a. 1, 2, 3, 4
b. 4, 3, 2, 1
c. 2, 1, 3, 4
d. 1, 3, 2, 4