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
Digoxin is used in CHF associated with: 
Select and explain. 
A. HOCM (Hypertrophic obstructive cardiomyopathy), B. High output failure, C. Atrial fibrillation with high ventricular rate, D. All of the above
C: Atrial fibrillation with high ventricular rate
Answer: C: Atrial fibrillation with high ventricular rate 
Explanation: Digitalis should be used for patients

Who remain symptomatic even on diuretics and ACE inhibitors.
With heart failure who are in atrial fibrillation and require ventricular rate control.

Note: Digitalis is contraindicated in HOCM and high output cardiac failure.