Answer:B) naturalistic observation
Step-by-step explanation:
Naturalistic observation occurs when a researcher observes the participants in their natural environment without manipulating the experiment. This is done when doing a laboratory experiments will be unreasonable for the research question. Participants may not behave normal when they are in a constrained environment where they know they are being watched , they may even alter their behaviour to suit what is expected.
In their natural environment people behaves normal especially when they know they are not being watched , Which will give Lilly a perfect presentation of how students normally behave in class during a test.