The appropriate answer is a. the conversion of radiant energy to chemical energy. Plants use light from the sun to convert carbon dioxide and water to glucose. An important bi-product of this reaction is oxygen which is vital to all life on earth. When humans consume glucose and do work they are converting chemical energy into heat energy and mechanical energy.
Nutrients and energy from the food (as well as water) we eat are absorbed in the intestines.
Oceanic crust is constantly formed at mid-ocean ridges, where tectonic plates are tearing apart from each other. As magma that wells up from these rifts in Earth's surface cools, it becomes young oceanic crust. ... Just as oceanic crust is formed at mid-ocean ridges, it is destroyed in subduction zones.