Answer:
b. The number of protons always changes when transmutation occurs.
Step-by-step explanation:
Transmutation is the process of changing one element into another by altering the number of protons in the nucleus of an atom. This can be achieved through natural radioactive decay or artificial means, such as nuclear reactions in a laboratory. When the number of protons changes, the identity of the element changes as well. The number of electrons, neutrons, and energy levels may or may not change during transmutation, depending on the specific reaction.