This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Which of the following is true about Digoxin 
Select and explain. 
A. It acts by inhibiting PDE 3, B. Dose reduction is not required in liver failure, C. Hyperkalemia predisposes to Digoxin toxicity, D. Atrial flutter is the most characteristic arrhythmia caused by Digoxin toxicity
B: Dose reduction is not required in liver failure
Answer: B: Dose reduction is not required in liver failure 
Explanation: Digoxin acts by inhibiting Na+- K+ ATPase.
Dose reduction is required in renal failure not liver failure.
Hypokalemia increases the risk of Digoxin toxicity.
Most common arrhythmia in Digoxin toxicity is most ventricular bigeminy.
Most characteristic arrhythmia seen in Digoxin toxicity is Atrial tachycardia + AV Nodal blockade.