The correct answer is number 4. The National Institutes of Health found it effective in reducing pain and other symptoms, but it is not clear how it works.
After reading the passage about acupuncture, the statement that supports the claim that acupuncture relieves pain is " The National Institutes of Health found it effective in reducing pain and other symptoms, but it is not clear how it works."
Acupuncture is an ancient Chinese practice that uses wired-thin needles that are inserted in determined parts of the body by the expert. The needles block the pain. Some believe the technique, others don't, saying that it only produces a placebo effect. The National Institutes of Health found it effective in reducing pain, reducing nausea and vomiting but it is not clear how it works.
