Given below are two statements: one is labelled as Assertion $\mathrm{A}$ and the other is labelled as Reason $\mathrm{R}$

Assertion $\mathrm{A}$: Boron is unable to form ${\mathrm{BF}}_6^{3-}$

Reason $\mathrm{R}$: Size of $\mathrm{B}$ is very small.

In the light of the above statements, choose the correct answer from the options given below

• A

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

  Both $\mathrm{A}$ and $\mathrm{R}$ are true but $\mathrm{R}$ is not the correct explanation of $\mathrm{A}$
• 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: 'B'.