Which of the Following Create a Higher Risk for Digoxin

Which of the following create a higher risk for digoxin toxicity? Both the cause and the reason for it must be correct.

A) Older adults because of reduced renal function
B) Administration of aldosterone antagonist diuretics because of decreased potassium levels
C) Taking an antacid for gastroesophageal reflux disease because it increases the absorption of digoxin
D) Doses between 0.25 and 0.5 mg/day