Multiple Choice the choice that best completes the statement or answers the question. 1. Which of the following best describes involuntary muscle responses? C. muscle movements that are under our conscious control; examples include moving of the arms and legs. muscle movements that are under Our cons lous control; examples include beating of the heart. b. les that are not under our conscious food. control;examples include digesting of d. muscles that are not under our conscious control; examples include curling the biceps when working out. 2. What two proteins play a vital role in the process of muscle contraction? a. actin+tropomyosin C. myosin+troponin b. dystrophin+troponin d. myosin+actin 3. What percentage of the human body's mass is made up of muscle tissue? a. 40% -50% b. 35% -45% C. 55% -65% d. 20% -30% 4.Which of the following best describes voluntary muscle responses? a. muscle movements that are under our conscious control; examples include moving of the arms and legs. C. muscles that are not under our conscious control; examples include digesting of food. b. muscle movements that are under our conscious control; examples include beating of the heart. d.muscle that are not under our conscious control; examples include curling the biceps when working out.