This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
The most common sourse of embolism - 
Select and explain. 
A. DVT, B. Trauma, C. Infection, D. Surgery
A: DVT
Answer: A: DVT 
Explanation: In greater than 95% of cases, venous emboli originate from thrombi within deep leg veins proximal to the popliteal fossa; embolization from lower leg thrombi is uncommon. Depending on size, a PE can occlude the main pulmonary aery, lodge at the bifurcation of the right and left pulmonary aeries (saddle embolus), or pass into the smaller, branching aerioles . Rarely, an embolus passes through an atrial or ventricular defect and enters the systemic circulation (paradoxical embolism) ( Robbins Basic Pathology, 9 th edition, page 90 )