Answer:
The correct answer would be- Hawthorne effect.
Explanation:
Hawthorne effect is the theory or reactivity that refers to the group of people who alter their behavior while knowing that they are observed. This change in behavior can affect the research or study and it's variables.
Such an effect caused due to knowing to fact that they are being examined not by the changes in a variable. This is what that mess with the result of the research or the study.
Thus, the correct answer is - Hawthorne effect