Answer:
The enthalpy change for the reaction is ΔH = - 54.3 kJ/mol
Explanation:
The reaction between HCl and NaOH is a neutralization reaction:

Heat released during neutralization = Heat gained by water
i.e. 
where:

m = total mass of solution

ΔT = change in temperature = 22.8 - 21.5 = 1.3 C
c = specific heat = 4.18 J/g C

As per equation (1): qrxn = -434.7 J
The reaction enthalpy ΔH is the heat released per mole of acid (or base)


According to Raoult's law, Vapor pressure is directly proportional to the mole fraction of the solution. As 1.0 M CaF2 has least moles here, it has lowest vapor pressure.
In short, Your Answer would be Option D
Hope this helps!