This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pharmacology
Drugs implicated in development of heart block include which of the following? 
Select and explain. 
A. Beta blockers, B. Lithium, C. Adenosine, D. All the above
D: All the above
Answer: D: All the above 
Explanation: Ans. is 'd' i.e., All the above * From the following table it is clear that all the given drugs are implicated in the development of Atrioventricular heart block.Drugs causing AV blockBeta blockers AdnosineClacium channel blockers Antiarrhythmics (class I and III)Digitalis Lithium