Answer:
she did not randomly assign participants to the experimental and control groups
Step-by-step explanation:
In the scenario being described, the thing that is mostly wrong with Diana's experiment is that she did not randomly assign participants to the experimental and control groups. By not assigning the individuals to random booths and creating a control group then the individuals all chose the booth that they thought they would enjoy the most. This, as well as not being able to compare the results of each group ultimately ruins the overall reason for the experiment.