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: Dental
Pulpal infection in primary mandibular posterior teeth is
first manifested on a radiograph in the area? 
Select and explain. 
A. Of bifurcation, B. At the apex of the root, C. Around the permanent tooth bud, D. Near the crest of alveolar bone
A: Of bifurcation
Answer: A: Of bifurcation 
Explanation: None