The correct option is A Reduction of emission of green house gases.
Kyoto
protocol is an international treaty. It is a convention on climate change. It
was adopted in Japanese city Kyoto in December, 1997. It mainly deals with the
reduction of emission of greenhouse gases that are responsible for the global
warming. Carbon dioxide, Carbon monoxide, Methane, Nitrous oxide, ozone, etc.
are the greenhouse gases. It was the most significant environmental treaty ever
negotiated.