Respuesta :

The answer is; plankton

The major group of plankton that contribute to earth’ crude oil are phytoplanktons because of their  great numbers – even though they are microscopic. They are the base of the food chains in the oceans because they are the main primary producers. Examples of phytoplankton are the dinoflagellates, cyanobacteria,  diatoms and blue-green algae.