Assertion (A): The Pamir mountains have been given the name 'Roof of the World'. Reason (R1): The Pamirs are in Asia Reason (R2): The Pamirs protect Asia from natural calamities.

• If only reason 1 (R1) and not reason 2 (R2) is the reason for the assertion (A).
• If only reason 2 (R2) and not reason 1 (R1) is the reason for the assertion (A).
• If both (R1) and (R2) are reasons for the assertion (A).
• If neither (R1) nor (R2) is the reason for the assertion (A).