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: Physiology
Cardiac index is defined as 
Select and explain. 
A. Stroke volume M2/BSA, B. Cardiac output per minute per unit body surface area, C. Systolic pressure/M2 BSA, D. End diastolic volume
B: Cardiac output per minute per unit body surface area
Answer: B: Cardiac output per minute per unit body surface area 
Explanation: Cardiac index- Cardiac output per minute per square meter of body surface area. Normal- 3.2L/min/ m2.