Which of the Following Statements Concerning the Cardiac Cycle Is

Multiple Choice

Which of the following statements concerning the cardiac cycle is true?

A) Blood enters the right and left atria only during diastole.
B) Most ventricular filling occurs before the atria contract.
C) During ventricular systole, the AV valves open.
D) The semilunar valves remain closed throughout ventricular systole.
E) Most of end-diastolic volume comes from active filling.