[单选题]
Which statement(s) ar)h v(u2zozsi* e true for AT lb-3p*x sldkyy5v)4s/rz1r oP hydrolysis during muscle contraction?
I. ATP is hydrolysed by the sarcoplasmic reticulum
II. ATP hydrolysis causes myosin heads to move into the ready position
III. ATP hydrolysis causes the cross-bridges to break