Answer:d. placebo effects
Explanation:
What Is the Placebo Effect?
- The placebo effect is a phenomenon in which a person may start to feel like an inactive substance has actual healed them or has given them some benefits.
A placebo is only an inactive ,non medical substance which has no medical effect on a person and ig could be sterile water , saline solution or a sugar pill.
People may experience real changes through a fake treatment because of their expectations of they expect it to work they would start to actual feel it work.
It occurs mostly when a person doesn't know that what they are receiving isn't real medicine
A double-blind study refers to when both experimenters and participants doesn't know which is drug and which isn't