Which of the Following Statements Is True Concerning the Diastolic

Which of the following statements is true concerning the diastolic depolarization phase of a cell in the SA node?

A) The cell will not depolarize until it receives sympathetic stimulation.
B) The pacemaker potential is caused by Ca²⁺ entering the cell via L-type Ca²⁺ channels.
C) The pacemaker potential is slower in achieving threshold when acetylcholine is applied to the SA node cells.
D) During diastolic depolarization, there is a gradually increasing permeability to K⁺.
E) The slope of the diastolic depolarization is decreased when norepinephrine is applied to the SA node cells.