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: Radiology
The radiopacity of zygoma is superimposed on roots of: 
Select and explain. 
A. Premolars, B. 1st and 2nd maxillary molar, C. Maxillary 3rd molar, D. All of the above
B: 1st and 2nd maxillary molar
Answer: B: 1st and 2nd maxillary molar 
Explanation: The radiopacity of zygoma is usually superimposed on the roots of 1st and 2nd maxillary molars, but not on the roots of 3rd molars.