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
Mature graffian follicle preovulatory is less than 
Select and explain. 
A. 12mm, B. 1.4mm, C. 18 mm, D. 25mm
C: 18 mm
Answer: C: 18 mm 
Explanation: 18 mm