In one research project, a scientist gave students subliminal cassette tapes and told them to play them for 2 months. after 2 months, she assessed whether the tapes the self-esteem of her participants and found that self-esteem had indeed risen! while she may have attributed this to the tapes, it is also possible that those students may have found college life to be manageable and thus experienced an increase in self-esteem for that reason. this demonstrates which principle of critical thinking?

I believe the answer is: Ruling out rival hypotheses

Rival hypothesis refers to two possible alternatives to explain a certain occurrence which would contradict one another. Ruling out rival hypotheses is really crucial in order to improve internal validity of the result, and usually carried out by using  control techniques (most important is random assignment).

this is an outline for the decisions that frankie is going to make

opportunity cost

willingness to buy

price or quality

of course, there could be many economic strategies that should be considered important while making decision. opportunity cost is the foremost significant factor while considering any economic option. when you buy something, you should know how much you are forgoing for this product. indeed, you could buy something different with this measure if you changed your mind. willingness to buy shows how much surplus you are earning while making a decision. it is important because it shows you buy what you want or you buy because you have only limited amount of money. the price or quality can be considered as a general economic option that we are applying while buying something. when you buy something, price or quality could be one of the options. indeed, they define the characteristics of the product.    

mark brainliest!