Assertion (A): Aluminium oxide is an amphoteric oxide.
Reason (R): Aluminium when heated in air forms aluminium oxide which shows both acidic and basic behavior.

A) Both assertion and reason are correct, and the reason is the correct explanation of the assertion.
B) Both assertion and reason are correct, but the reason is not the correct explanation of the assertion.
C) Assertion is correct, but the reason is incorrect.
D) Assertion is incorrect, but the reason is correct.