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
Atomic weight is equal to total number of: 
Select and explain. 
A. Protons, B. Protons and neutrons, C. Protons and electrons, D. Protons, neutrons and electrons
B: Protons and neutrons
Answer: B: Protons and neutrons 
Explanation: Ans. Protons, neutrons and electrons