20) In order for high force cross bridges to form in contracting skeletal muscle, calcium must A) phosphorylate the troponin to move the tropomyosin. B) bind to calmodulin to phosphorylate the myosin. C) phosphorylate the tropomyosin which moves it. D) bind to tropomyosin which moves the troponin. E) bind to troponin which moves the tropomyosin.