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 disease is/are 
Select and explain. 
A. Small and medium sized vessels involved, B. Commonly involves upper limb than lower limbs, C. Common in male, D. Common in female
A: Small and medium sized vessels involved
Answer: A: Small and medium sized vessels involved 
Explanation: None