The correct option is D cation
When an acid reacts with a base, it forms salt along with water and this reaction is known as neutralisation reaction.
In this reaction, anion from an acid combines with the cation of a base to form the salt.
Example:
NaOH(aq)+HCl(aq)→NaCl(aq)+H2O(l)
In NaCl, Na+ ion is from the base while the Cl− ion is from the acid.