Answer: A
Explanation: It makes the most sense because it isn't directly speaking about something, it is mainly summarizing the main idea. I'm not 100%, but that's the one I would choose if it were me. Hope I helped out a little!
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.