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 \(KCl\) [atomic masses of \(K\) and \(Cl\) are \(39\) and \(35.5\, g \,mol ^{-1}\) ]. 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 with temperature. In the light of the above statements, choose the correct answer from the options given below

1. A Both \((A)\) and \((R)\) are true and \((R)\) is the correct explanation of \((A)\)
2. B Both \((A)\) and \((R)\) are true but \((R)\) is not the correct explanation of \((A)\)
3. C \((A)\) is true but \(( R )\) is false
4. D \((A)\) is false but \((R)\) is true