The correct options are
A Destruction of coral reefs
B Volcanic eruptions
C Earthquakes
D Tsunamis
Global warming is basically an increase in the average global surface temperature. Oceans form 70% of the earth’s surface, and they absorb more heat than land, causing an increase in the average ocean temperatures on the planet. This adversely affects aquatic life, particularly, sensitive (yet rich) marine ecosystems such as coral reefs. Excessive melting of ice caps as a result of global warming can reduce the weight borne by land, which can often bounce back upon land in the form of earthquakes or volcanic eruptions (by causing a disturbance in the continental plates and/or the magma under them). The melting of ice caps apparently, could add to the load in oceans which too, can result in tsunamis and volcanic eruptions.