In order to stop experimental subjects from trying to confirm the scientist's hypothesis, psychologists sometimes obtain written promises from participants to be honest maintain subject confidentiality deceive participants about the true purpose of the experiment allow people to choose when they want to leave the study remove participants from the study before it starts

C deceive participants

Explanation:

It is ethical practice to come clean or tell the truth about being deceptive at the end of the study.  They need to be told that they were deceived.  

myth. it was once thought that animals, including cats and dogs, could only see in black and white. however, scientists have proven this to be a myth. in all animals, including humans, the perception of colour is determined by the presence of cells in the eye called cone photoreceptors.