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
Body temperature is maintained by: 
Select and explain. 
A. Postural position, B. Covering of the body, C. Peripheral vasoconstriction, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: None