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: Gynaecology & Obstetrics
Best diagnosis of ovulation is by : 
Select and explain. 
A. Ultrasound, B. Laproscopy, C. Endometrial biopsy, D. Chromotubation
A: Ultrasound
Answer: A: Ultrasound 
Explanation: Ultrasound