12. During skeletal muscle contraction, multiple crossbridge cycles are occurring between the same thick and thin filament. Which of the following best describes this process?
(A) Crossbridge cycling is highly synchronized between a certain thick and thin filament.
(B) Crossbridge cycling is asynchronous between a certain thick and thin filament.
(C) No more than one myosin head links to the thin filament at the same time.
(D) No more than one myosin head detaches from the thin filament at the same time.
(E) Tropomyosin only exposes one binding site on actin at a time allowing only one crossbridge to form with actin at a given time.