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
The formation of primordial follicles in human fetus is completed by : 
Select and explain. 
A. 4 weeks, B. 8 weeks, C. 13 weeks, D. 18 weeks
D: 18 weeks
Answer: D: 18 weeks 
Explanation: 18 weeks