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
Number of ossification centres in femur is: 
Select and explain. 
A. 2, B. 4, C. 5, D. 7
C: 5
Answer: C: 5 
Explanation: The femur ossifies from five centres: in the shaft, head, greater and lesser trochanters and the distal end. Other than the clavicle, it is the first long bone to ossify.