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 of the following are true about blood coagulation, except \nSelect and explain. \nA. Factor X is part of both intristic and extrinsic path ways, B. Extrinsic pathway is activatied by contact with negatively charged surfaces, C. Intrinsic pathway can be activated in vitro, D. Calcium is required in several steps of coagulation', 'role': 'user'}, {'content': 'Answer: B \nExplanation: harshmohan textbook of pathology 7 th edition extrinsic pathway is activated only by tissue damage which causes release of thromboplastin where as intrinsic pathway is activated by surface contact. factor x is a part of common pathway. \nCa2+ is required for conversion of 1x -1xa ,prothrombin to thrombin', 'role': 'assistant'}]