Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason $\mathrm{R}$. Assertion $\mathrm{A}$ : $\mathrm{LiF}$ is sparingly soluble in water. Reason $\mathrm{R}$ : The ionic radius of ${\mathrm{Li}}^{+}$ ion is smallest among its group members, hence has least hydration enthalpy.

In the light of the above statements, choose the most appropriate answer from the options given below.

• A

  Both $\mathrm{A}$ and $\mathrm{R}$ are true and $\mathrm{R}$ is the correct explanation of $\mathrm{A}$
• B

  Both $\mathrm{A}$ and $\mathrm{R}$ are true but $\mathrm{R}$ is NOT the correct explanation of $\mathrm{A}$
• Correct answer
  C

  $\mathrm{A}$ is true but $\mathrm{R}$ is false
• D

  $\mathrm{A}$ is false but $\mathrm{R}$ is true

Hence, the correct answer is option: 'C'.