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
Ideal drug employed in the preoperative preparation for surgical excision of pheochromocytoma is: 
Select and explain. 
A. Atenolol, B. Phenoxybenzamine, C. Reserpine, D. Clonidine
B: Phenoxybenzamine
Answer: B: Phenoxybenzamine 
Explanation: None