Option C, cation.
In chemistry, there are two types of ions: cation and anion. A cation essentially means that the atom is positively charged, which happens when atoms lose an electron. An anion means that it's negatively charged, which happens when atoms gain an electron
My middle school chemistry teacher told me a good way to remember the difference. A cation's sounds like "cat," and that's positive (Who doesn't like cats?). Anion sounds like "onion," and that sounds negative (Ew, raw onion!).
If you have any questions, just ask. Good luck! :))
-T.B.
