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
Modified shock index is 
Select and explain. 
A. Heart rate/ systolic BP, B. Heart rate/ Diastolic BP, C. Heart rate/ Mean arterial pressure, D. None of the above
C: Heart rate/ Mean arterial pressure
Answer: C: Heart rate/ Mean arterial pressure 
Explanation: None