Which of These Statements Correctly Describes the AV Nodal Delay

Multiple Choice

Which of these statements correctly describes the AV nodal delay?

A) It ensures that the atria contract and empty their contents into the ventricles prior to ventricular systole.
B) It ensures that the ventricles contract prior to atrial systole.
C) It ensures that tetanic contraction of cardiac muscle is impossible.
D) It is shortened by parasympathetic stimulation.