Final answer:
Morphine is the substance that does not belong in the same group as oxycodone, hydrocodone, and fentanyl because it is a natural opioid derived directly from the opium poppy, while the others are synthetic opioids.
Step-by-step explanation:
The question is asking which of the following substances does not belong in the same group: oxycodone, hydrocodone, morphine, and fentanyl. All these substances are opioid drugs used to manage pain, but morphine is the one that stands out. While oxycodone, hydrocodone, and fentanyl are synthetic opioids, morphine is a natural opioid directly derived from the opium poppy. Morphine is often used before and after surgical procedures to alleviate severe pain, while oxycodone is also often prescribed for moderate to severe pain. Both hydrocodone and fentanyl have similar applications, with fentanyl being particularly potent and also used in chronic pain management. However, Morphine's distinction lies in its direct origin from the poppy plant, without the synthetic process that characterizes the others.