Answer:
true
Step-by-step explanation:
Doctors (or scientists) usually use this to make sure people aren't lying about the experience.
For example, some people might expect that if they take ibuprofen or Tylenol, they won't feel as much pain, so they might make themselves believe that they aren't feeling said pain. If you use a placebo group, you are less likely to have situations like that occur, and so your data becomes more accurate.