Below are two statements, one labeled as Assertion $(A)$ and the other as Reason $(R):$

Assertion $(A)$: Among group $13$ elements, boron's melting point is unusually high $(2453 \mathrm{~K})$.

Reason $(R):$ Solid boron has a strong crystalline lattice.

In the context of the above statements, choose the correct answer from the following options:

Which one of the following elements is unable to form $MF_{6}^{3-}$ ion?

Crystalline metal can be transformed into metallic glass by

${H_3}B{O_3} + {H_2}O_2 \to {H_2}O + 'X' {\xrightarrow{{NAOH}} }{'Y'}$

Which of the following statements is $/$ are Correct for $'Y'$

Why is boric acid considered as a weak acid ?