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: Medicine
Shy Drager syndrome is: 
Select and explain. 
A. Intestinal polyp, B. Acute adernergic shock, C. Vasovagal hypotension, D. Orthostatic hypotension
D: Orthostatic hypotension
Answer: D: Orthostatic hypotension 
Explanation: None