You Decide to Do an Experiment with Isolated Myofibrils to Explore

You decide to do an experiment with isolated myofibrils to explore the effects of ATP hydrolysis on myofibril function. You do this by bathing the myofibrils in a solution that contains a modified form of ATP, which cannot be split into ADP and P_i. At what step will myofibril function be arrested by using this compound instead of unmodified ATP?

A) Myosin heads will bind to the actin filaments, but the power stroke will not occur and actin filaments will not slide over the myosin filaments.
B) Myosin molecules will be unable to assemble into thick filaments.
C) Myosin heads will be unable to bind to the actin filaments.
D) There will be no block in the cycle, since ATP hydrolysis is not required for this process.
E) The myosin heads will remain attached to the actin filaments after the power stroke.