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: Medicine
A 65 year old woman after knee implant surgery complains of calf pain and swelling in the leg, from last 2 days. Later the
complains of breathlessness and dies suddently in the ward Probable cause - 
Select and explain. 
A. Pulmonary embolism, B. Myocardial infarction, C. Stroke, D. ARDS
A: Pulmonary embolism
Answer: A: Pulmonary embolism 
Explanation: None