The correct option is
D Both assertion and reason are correct statements, and reason is the correct explanation of the assertion
Analysing the assertion
Rhombic sulphur and monoclinic sulphur are allotropes of sulphur that exist as
S8, while oxygen exist as
O2.
The structure of
S8 is puckered and has a crown shape while the structure of
O2 is linear.
The assertion is correct as oxygen cannot exist in polyatomic forms like Sulphur.
Analyzing the reason
This is because due to small size of oxygen, it can form
pπ−pπ multiple bonds but due to larger size of sulphur it cannot form
pπ−pπ multiple bonds as orbital overlapping will be very weak and thus only single bond is present between sulphur atoms in
S8 molecules.
So, the reason is also correct.
Hence, assertion and reason both are correct, and reason is the correct explanation of assertion.
Hence, option (A) is correct.