Answer:
C
Explanation:
If you have more than one variable then you wont know which variable caused the change. Hope this helped, if it did give it a thanks or whatever.
The answer should be: codeine, hydrocodone, oxycodone or tramadol
Opioid drugs are frequently used to treat pain. Acetaminophen, aspirin or NSAIDs drug used for mild to moderate pain. The mild opioid will be used in moderate to severe pain while a strong opioid will be used in severe pain. Strong opioid that could be used for severe pain would be morphine, methadone, oxycodone, or fentanyl