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: Psychiatry
Oniomania is a disorder of compulsive - 
Select and explain. 
A. Buying, B. Cellular phone use, C. Internet use, D. Selfmultilation
A: Buying
Answer: A: Buying 
Explanation: Oniomania is compulsive buying.