I'm pretty sure the correct answer is C. Hope i wasn't to late.
Answer:
Cross-sectional research.
Explanation:
Here's a definition: Cross sectional research is a study in which subjects of different ages are compared at the same time.
Answer:
I'm not quite sure this is an answer it gives, but with lack of water people become week and tend to do anything to satisfy their thirst. Therefore the advantage point could be the fact that people were weak.
Explanation: