Red Seal Plumbing Practice Exam

An anion is a negatively charged ion in solution, which means it cannot be an option. A proton is a positively charged particle within an atom, but it does not refer to a positively charged ion in solution. A neutron is an uncharged particle within an atom, so it cannot be an option. Therefore, cation is the only correct option as it specifically refers to a positively charged ion in solution.