C. Dinosaur footprint as it is the only body part that is stated in the choices.
Hope this helps :)
The increase of carbon dioxide in the atmosphere creates a greenhouse effect.
To explain this usually some sunlight is reflected back into space while some is absorbed by the earth keeping the planet warm. However the increase in greenhouse gases such as carbon dioxide prevent the light from reflecting back into space and this light becomes trapped causing the earth to heat more then it should. You can almost think of the trapped heat from the greenhouse gases as a blanket around the earth trapping the heat in.
The answer u r looking for is- D* failure of the immune system to distinguish self from nonself. Hope I’ve helped ;)
The greek root-word Bios means life