This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CHF, Angina Pectoris and Myocardial Infarction, Subject name: Pharmacology
Which of the following anti-arrhythmic drugs is useful in AV block resulting from digoxin overdose? 
Select and explain. 
A. Adrenaline, B. Noradrenaline, C. Atropine, D. Adenosine
C: Atropine
Answer: C: Atropine 
Explanation: Treatment of digoxin toxicity: Mild digitalis toxicity Decreased with K+ (It decreases binding of the drug to Na+K+ATPase) but in severe digitalis toxicity, K+ is C/I Ventricular arrhythmias Lignocaine Atrial tachyarrhythmia b blockers Bradyarrhythmias and AV block Atropine Very severe toxicity Digibind