Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A):At $10^{\circ} \mathrm{C}$, the density of a 5 M solution of KCl [atomic masses of K and Cl are $39 \& 35.5 \mathrm{~g} <\mathrm{~mol}^{-1}$ ]. The solution is cooled to $-21^{\circ} \mathrm{C}$. The molality of the solution will remain unchanged.
Reason (R) : The molality of a solution does not change with temperature as mass remains unaffected with temperature.
In the light of the above statements, choose the correct answer from the options given below: