An Elderly Patient with a History of Sodium Retention Arrives

An elderly patient with a history of sodium retention arrives to the clinic with the complaints of "heart skipping beats" and leg tremors. Which of the following should the nurse ask this patient regarding these symptoms?

A) "Have you stopped taking your digoxin medication?"
B) "When was the last time you had a bowel movement?"
C) "Were you doing any unusual physical activity?"
D) "Are you using a salt substitute?"