The answer is E; Self-interest study. This is due to the fact that the financier of the research, the beverage company, has vested interests in the research and will therefore be intuitively biased for the results to favour the sales of the beverage.
Natural gas is a fossil fuel used as a source of energy for heating, cooking, and electricity<span> generation. It is also used as fuel for vehicles and as a chemical feedstock in the manufacture of plastics and other commercially important organic chemicals.</span>
I would say commensalism since one organism benefits (the seeds) and the other other is neither benefited nor harmed