$A$ molar solution is one that contains one mole of a solute in

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: At $10^{\circ} C$,the density of a $5 \ M$ solution of $KCl$ is given. The solution is cooled to $-21^{\circ} C$. The molality of the solution will remain unchanged.
Reason $R$: The molality of a solution does not change with temperature as mass remains unaffected by temperature.
In the light of the above statements,choose the correct answer from the options given below:

Calculate the density of an aqueous solution of $KI$,if its molarity and molality are $1.44 \ M$ and $1.5 \ mol \ kg^{-1}$ respectively. (in $g \ mL^{-1}$)

The molarity of the solution obtained by mixing $800 \ mL$ of $0.5 \ M$ $HCl$ and $200 \ mL$ of $1 \ M$ $HCl$ will be ....... $M$.

If the density of some lake water is $1.25\, g\, mL^{-1}$ and contains $92\, g$ of $Na^{+}$ ions per $kg$ of water,calculate the molality of $Na^{+}$ ions in the lake. (in $, m$)

The molality (in $mol \ kg^{-1}$) of $1 \ mol$ of solute in $50 \ g$ of solvent is