Final answer:
NaF would have the highest melting point among the options because fluorine is the smallest halogen, leading to a stronger electrostatic attraction between the Na+ and F- ions.
Step-by-step explanation:
The question asks about the melting points of various sodium halide compounds. When comparing the melting points of ionic compounds, we consider the strength of ionic bonds. Ionic bonds are influenced by the charge and the size of the ions. Since NaF, NaCl, NaBr, and NaI are all composed of ions with a +1 and -1 charge, we focus on the ionic radii.
Fluorine is the smallest halogen compared to chlorine, bromine, and iodine, which leads to stronger electrostatic attraction between Na+ and F- ions and results in a higher melting point for NaF. Therefore, NaF (A) would have the highest melting point among the given options.