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
Deep vein thombosis occurs most commonly after - 
Select and explain. 
A. Total hip replacement, B. Gastrectomy, C. Prostatic operation, D. Brain surgery
A: Total hip replacement
Answer: A: Total hip replacement 
Explanation: The factors which result in increased risk of venous thrombosis include advancing age and greater complexity of surgical treatment. Orthopedic operations on the lower limbs (hip and knee replacements) are especially likely to result in venous thrombosis." - Bailey & Love