A 59-year-old obese woman with a history of diabetes mellitus had a myocardial infarction 3 months ago. She is now taking a low dose of aspirin to reduce the risk of arterial thrombosis. On which of the following steps in hemostasis does aspirin have its greatest effect?
(A) Adhesion of platelets to collagen
(B) Aggregation of platelets
(C) Production of tissue factor
(D) Synthesis of von Willebrand factor
(E) Synthesis of antithrombin III