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: Pediatrics
Normally, Cortisol levels are maximum at __________ and lowest at ________ 
Select and explain. 
A. 8 pm and eary morning, B. 12 pm and 12 am, C. 8 am and 8 pm, D. 8 am and midnight
D: 8 am and midnight
Answer: D: 8 am and midnight 
Explanation: None