When we have an ionic compound we are talking about a compound that has an ionic bonding linking both elements, and these types of bonding will occur mostly with metals (such as Na and Ca) and nonmetals (such as Cl and F).
The main characteristic of this type of bond is the donation of electrons, most of the time the metal will give up on its electrons and the nonmetal will receive the element in order to fill its valence shell, this is how the charges are produced, we will have a positive charge and a negative charge in ionic compounds.
Something particular to this type of bond is that it is considered a very strong bond, where in order to break it a lot of energy is required. The strength of a bond is reflected on the melting and boiling points, since ionic compounds have a very strong bond, the temperature to melt and boil will be high
According to this explanation, the temperature that makes the most sense it will be 115°C, which is the highest temperature from the given options, therefore letter A