This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: The Ovarian Cycle, Subject name: Gynaecology & Obstetrics
[{'content': 'Ovulation can be evaluated by? \nSelect and explain. \nA. Cervical mucous, B. Cervical colour, C. Cervical dilation, D. Cervical effacement', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ANSWER: (A) Cervical mucousREF: Shaw 13th ed p. 213"Cervical mucus changes can be used to assess ovulation using the fern test"', 'role': 'assistant'}]