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: Forensic Medicine
All the primary ossification centers are appeared at fetal age of: WB 11 
Select and explain. 
A. 1 month, B. 2 months, C. 3 months, D. 4 months
D: 4 months
Answer: D: 4 months 
Explanation: Ans. 4 months