If the following events were placed in chronological order which would come fourth?

The answer is C. During surgery and post operatively (A) stasis occurs in the deep veins in the calves (E) resulting in thrombosis (B); fragments of thrombus break off into the circulation (C), plug the pulmonary arteries and cause infarction (D). A significant number of emboli come from thrombosis of pelvic veins.