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
Female menstrual cycle is diagnosed by 
Select and explain. 
A. Sex steroid profile, B. Basal body temperature, C. Vaginal cell cytology, D. Cervical mucus test
A: Sex steroid profile
Answer: A: Sex steroid profile 
Explanation: None