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
Fetal stage starts at: 
Select and explain. 
A. 9 weeks, B. 3 weeks, C. 6 weeks, D. 12 weeks
A: 9 weeks
Answer: A: 9 weeks 
Explanation: Fetal Growth Periods