It is A. they are made from planets materials and animal matter. Biofuels comes from anything that was alive. This does not include fossil fuels. Example: ethanol made from corn. A corn is a plant that is a living thing.
There will be no food for carnivores if herbivores were removed in the food web.
The temperature would continue to increase, the closer you were to the mantle of the Earth.
Well for it to be valid you are going to need a hypothesis,control,and variables. The control should be the plant food since it stays constant. And the variables should be the 2 different plants.
