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: Pathology
[{'content': 'All are to access platelet functions except ? \nSelect and explain. \nA. Prothrombin time, B. Bleeding time, C. Clot retraction time, D. all', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Prothrombin time", 'role': 'assistant'}]