Assertion : Beryllium resembles aluminium.

Reason : : Charge / radius of $B{e}^{2+}$ ion is nearly the same as that of the $A{l}^{3+}$ ion.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
3. If the assertion is true but the reason is false
4. If both the assertion and reason are false