Answer: C) She didn't randomly assign participants to the experimental and control groups.
Explanation: It is necessary to randomly assign people to hot or cool units becasue if you give people a choice, they will automatically select the room with the temperature they prefer which would overthrow the point of the experiment.
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Option A, C, and D would be the answers
By finding a common interest that both of those people would have whether it is music, Political views, culture or religion etc;
