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
Maximum recommended dose for dental X-ray operator in a week is 
Select and explain. 
A. 100 milliroentgen, B. 10 roentgen, C. 100 roentgen, D. 300 roentgen
A: 100 milliroentgen
Answer: A: 100 milliroentgen 
Explanation: None