Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : Boron is unable to form $\mathrm{BF}_{6}^{3-}$.

Reason (R) : Size of B is very small.

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) Correct answer
3. C (A) is true but (R) is false
4. D (A) is false but (R) is true