DrTracy Conducts an Experiment Where Participants Are Given a Mild

Dr.Tracy conducts an experiment where participants are given a mild shock followed by either a placebo or an opioid.When Dr.Tracy asks participants about pain relief and studies pain-related areas of their brains, what will Dr.Tracy find?

A) Both the placebo and the opioid drug relieved pain, but only the opioid affected the region responsible for the control of the pain response in the brain.
B) The placebo reduced pain but didn't relieve pain as well as the opioid drug.
C) Both the placebo and the opioid drug relieved pain, and they affected similar regions in the brain stem.
D) Both the placebo and the opioid drug relieved pain, but they affected completely different regions in the brain.