Answer: Experiment
Explanation: An experiment could be explained as a scientific or empirical process or procedure embarked upon in other to establish a fact, test an hypothesis for rejection or acceptance or make a breakthrough in a certain field of discovery. Experiments may be undertaken to establish the chemical, biological, physical or psychological effect, Response, behavior or nature of an object, animal or species under certain conditions.
In the scenario above, the research is trying to establish or discover the relationship or correlation between stress and blood pressure by experimenting participants under two different conditions.
