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: Medicine
[{'content': "Hess's (Tourniquet) test is a feature of - \nSelect and explain. \nA. Idiopathic Thrombocytopenic Purpura (I.T.P), B. Secondary thrombocytopenia, C. Allergic purpura, D. Senile purpura", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]