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: Anatomy
The first centres of ossification appears during which month of pregnancy 
Select and explain. 
A. At the end of 2nd month of pregnancy, B. At the beginning of 3rd month of pregnancy, C. At the end of 3rd month of pregnancy, D. At the end of 4th month of pregnancy
A: At the end of 2nd month of pregnancy
Answer: A: At the end of 2nd month of pregnancy 
Explanation: A i.e. At the end of 2nd month of pregnancy Clavicle is the first bone in the body to sta ossifying and is ossified from 3 centres. The shaft of clavicle is ossified from 2 (medical & lateral) primary centres, which appear between the 5th & 6", weeks of intra uterine life, and fuse about the 45th day meeting between the middle and lateral third of clavicle. A secondary centre for sternal end (and sometimes for acromial end) appears in late teens or early twenties