The correct option is D 1, 2, 3 and 4
Global warming is the long-term heating of the earth's climate due to human activities which increases the level of greenhouse gases in the earth’s atmosphere. This has had a drastic effect on earth resulting in unprecedented climate changes such as droughts, floods, forest fires, cyclones etc.
These have in turn affected crop yield, plant and animal life which also stand to be threatened. Climatic changes have also led to the increased melting of polar ice caps as well as the Himalayan snow caps. Over many years, this will result in a cumulative rise in sea level that can submerge many coastal areas.