Deena, a research student, decides to test the proverb "birds of a feather flock together" as part of her research project. in this scenario, is most likely to be the initial source of deena's idea. practical problems past research scientific theory common sense

The answer is "common sense".

The initial source has to be common sense as idioms are usually metaphorical statements which make sense and relate to the common life.

In nature, birds of a solitary group do in actuality regularly frame groups. Ornithologists clarify this conduct as a 'security in numbers' strategy to diminish the danger of predation. In dialect terms, it was beforehand more typical to allude to birds flying together than flocking together and numerous early references utilize that frame.

what is the other part to the question

well considering i can't see the graph, it's probably prices