UV-Visible Spectroscopy in the analysis of sodium chloride in potato chips

Here is the question and answer out of an exam paper:

Firstly, I thought UV-Visible can also use radiation in the visible spectrum. Also when analyzing sodium chloride (a molecule), then UV-Visible would be more appropriate than AAS, because AAS would be used for just Na (Sodium). Would I be wrong to have said UV-Visible?