This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nuclear medicine, Subject name: Radiology
[{'content': 'Two nuclides having same number of neutrons but differ in protons number: \nSelect and explain. \nA. Isotopes, B. Isobars, C. Isotones, D. Isomers', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Isotone - Have the very same neutron number, but different proton number. Isotope - Two forms of same element containing equal numbers of protons but different numbers of neutrons in their nuclei, like a radioactive form of an element. Isobar - Isobars are atoms of different chemical elements that have the same number of nucleons. They have same mass number (Sum of protons plus neutrons). Isomers - Each of two or more compounds with the same formula but a different arrangement of atoms in the molecule and different propeies', 'role': 'assistant'}]