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 output is not affected by: 
Select and explain. 
A. Heart rate, B. Peripheral resistance, C. Systolic blood pressure, D. Venous return
C: Systolic blood pressure
Answer: C: Systolic blood pressure 
Explanation: None