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': 'Modified shock index is \nSelect and explain. \nA. Heart rate/ systolic BP, B. Heart rate/ Diastolic BP, C. Heart rate/ Mean arterial pressure, D. None of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]