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
Most serious adverse effect of ketoconazole is : 
Select and explain. 
A. Adrenal insufficiency, B. Pellagra like skin lesion, C. Liver injury, D. Prostate cancer
A: Adrenal insufficiency
Answer: A: Adrenal insufficiency 
Explanation: None