Use enthalpies of formation to determine the ΔHreaction for the reaction CaCl2(s)---> CaCl2(aq).

The enthalpy is increased by the increased heat of the reaction.

Explanation:

In this reaction, as the transition from solid to liquid state, enthalpy increases, that is, the heat applied to change its state is greater and this increases, reaching a mayor disorder.

If the reaction increases its heat, and a liquid state passes, the enthalpy increases, therefore the disorder also and the entropy will also be increased.

it is b that is the answer.