Assertion: Sulphur exist as $S_8$ but oxygen exists as $O_2$.
Reason: Oxygen forms $p\pi -p\pi$ multiple bond due to small size and small bond length but $p\pi -p\pi$ bonding is not possible in sulphur.

Assertion is correct, but reason is wrong statement. 

Both assertion and reason are correct statements, but reason is not the correct explanation of the assertion

Both assertion and reason are correct statements, and reason is the correct explanation of the assertion

Assertion is wrong but reason is correct statement