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: Surgery
True statement of Buerger's desease is/are -a) Small and medium sized vessels involvedb) Commonly involves upper limb than lower limbsc) Common in maled) Common in female 
Select and explain. 
A. a, B. bc, C. ac, D. b
C: ac
Answer: C: ac 
Explanation: Buerger's ds. may involve both upper or lower extremity. It is more common in lower limbs