Given below are two statements one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Rio 'Earth Summit of 1992 was the international conference on climate change.
Reason (R): The most significant international agreement on climate change was the Kyoto Protocol, negotiated in 1997.
In the light of the above statements, choose the most appropriate answer from the options given below: