Dr. Gong conducts a study where she randomly assigns participants to different experimental conditions. The testing for each condition occurs in a different room of the psychology building. After collecting her data, she learns that the air conditioning in one of the rooms had been turned off during data collection. Which of the following threats to internal validity should Dr. Gong be concerned with?

A. Design confound
B. Selection effect
C. Order effect
D. Maturation effect

A- Design confound

Explanation:

A design confound is method in an experiment that creates an extra variable that was not  accounted for which can ruin an experiment and give you wrong results by suggesting  correlation or creating a  bias. This  threatens internal validity due to its relationship with the dependent and independent variables, because it suggests that the study is not testing for what it should test for.

it is very necessary to identify one and avoid them to avoid  disrupting an experiment

Dr gong in this case finding out the air conditioning had been turned off during experiment when it needed to be on during the collection (ie one variable has been challenged) has given her a threat to internal validity of her results in the experiment.

i think the answer is true

"choosing is refusing" means individuals face an opportunity cost with each decision they make. economists state that every decision involves trade-offs. opportunity cost is the least desirable alternative given up as a result of a decision.