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: Pharmacology
[{'content': 'Aspirin produces all of the following effects except \nSelect and explain. \nA. Frank gastric bleeding, B. Prolonged prothrombin time, C. Platelet dysfunction, D. Constipation', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]