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
Drug of choice for acute adrenal insufficiency is ? 
Select and explain. 
A. Oral prednisone, B. IV hydrocortisone, C. IV betamethasone, D. IV dexamethasone
B: IV hydrocortisone
Answer: B: IV hydrocortisone 
Explanation: None