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
Pulsating varicose vein in a young adult is due to- 
Select and explain. 
A. Arteriovenous fistula, B. Sapheno femoral incompetence, C. Deep vein thrombosis, D. Abdominal tumour
A: Arteriovenous fistula
Answer: A: Arteriovenous fistula 
Explanation: None