(05.01 MC)Reseаrchers wаnted tо investigаte the relatiоnship between hоusehold chores and emotional well-being. Participants volunteered for a study to test a new cleaning product. During the study and without warning, researchers played distressing videos of personal tragedies and natural disasters to create a stressful environment for the participants. Following the videos, the new product was introduced. After using the product, participants were asked to rate their emotional well-being. Most of the participants reported they felt tricked. Which of the following ethical guidelines was not followed and resulted in the feeling of being tricked?