$BCl_3$ and $AlCl_3$ exist in $:-$

Boric acid is an acid because its molecule

Draw the structure of boric acid showing hydrogen bonding. Which species is present in water? What is the hybridization of boron in this species?

Which of the following reactions will yield the crystalline variety of boron?

Give the increasing order of group $13$ elements for atomic radius.

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 $(2453 \ K)$.
Reason $(R):$ Solid boron has a strong crystalline lattice.
In the context of the above statements,choose the correct answer from the following options: