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
At birth, mental foramen opens: 
Select and explain. 
A. Below sockets of deciduous canines, B. In front of socket of deciduous canine, C. Below sockets of deciduous molars, D. Behind sockets of deciduous molars
C: Below sockets of deciduous molars
Answer: C: Below sockets of deciduous molars 
Explanation: Key concept:
At birth the mental foramen, opens below the sockets for the two deciduous molar teeth near the lower border.
This is so because the bone is made up only of the alveolar part with teeth sockets. The mandibular  canal runs near the lower border. The foramen and canal gradually shift upwards.