During the isovolumic relaxation (also referred to isovolumetric relaxation) phase of the cardiac cycle:(A) The atrioventricular valves and semilunar valves are closed.(B) The atrioventricular valves and semilunar valves are open.(C) The atrioventricular valves closed and semilunar valves are open.(D) The atrioventricular valves open and semilunar valves are closed.(E) None of the above. Checking your answer...