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: Medicine
All of the following are associated with Atrioventricular block, except: 
Select and explain. 
A. Hyperkalemia, B. Hypomagnesemia, C. Hypothyroidism, D. Cushing's syndrome
D: Cushing's syndrome
Answer: D: Cushing's syndrome 
Explanation: Adrenal insufficiency is associated with Atrioventricular Block (Not cushing&;s syndrome). Metabolic/Endocrine Causes of AV Block: Hyperkalemia Hypermagnesemia Hypothyroidism Adrenal Insufficiency Ref: Harrison 19th edition Pg no: 1471