Given: 2NaCl the 2 is:

A. a coefficient that represents the number of sodium atoms in the molecule.

B. A subscript that represents the number of sodium atoms in the molecule.

C. A coefficient that represents the number of sodium chloride molecules.

D. A subscript that represents the number of sodium chloride molecules.

The answer to your question is the letter C.

Explanation:

Data

2NaCl

When we write molecules we use numbers in two main different ways.

If the coefficients are at the beginning of the molecule, this number indicates the number of molecules presented.

If there are subscripts, this number indicates the quantity of that specific element.

So the correct answer is letter C because it describe the correct function of this coefficient.