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

Assertion (A) : Melting point of Boron (2453 K) is unusually high in group 13 elements. 

Reason (R) : Solid Boron has very strong crystalline lattice.

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

Assertion (A): Melting point of Boron (2453 K) is unusually high in group 13 elements. This is true - Boron has the highest melting point among group 13 elements.

Reason (R): Solid Boron has very strong crystalline lattice. This is true - Boron exists in an icosahedral crystalline structure with very strong covalent bonds, giving it a very high melting point.

The reason correctly explains the assertion - the strong crystalline lattice of boron is why it has an unusually high melting point.

Both (A) and (R) are correct and (R) is the correct explanation of (A). The answer corresponds to Option (2).