<u>Answer:</u> The correct answer is
is the base and
is the salt.
<u>Explanation:</u>
Neutralization reaction is defined as the reaction in which an acid reacts with a base to produce salt and water as products.
According to the Bronsted-Lowry conjugate acid-base theory, an acid is defined as a substance which looses donates protons and a base is defined as a substance which accepts protons.
For the given chemical reaction:

Here,
is a base because it is accepting proton and HCl is an acid because it is loosing proton.
is considered as a salt because it is formed by the combination of acid and base.
Hence, the correct answer is
is the base and
is the salt.