Final answer:
Option (b) bromine is an isotope of bromine, while the other elements listed are not isotopes of bromine.
Step-by-step explanation:
Bromine has two isotopes: 79Br and 81Br. To determine which of the following is an isotope of bromine, we need to check their atomic masses. Based on the information provided, bromine (Br) would be an isotope of itself, so option (b) bromine is correct. The other elements listed are not isotopes of bromine.