Which of the following is a narcotic derived from the opium poppy?

Fentanyl is a synthetic opioid that is derived from the opium poppy, making it a narcotic. Opioids, in general, act on the body's opioid receptors, providing pain relief and producing feelings of euphoria, which are characteristics of narcotics. Fentanyl is significantly more potent than many other opioids and is prescribed for severe pain management.

Acetaminophen, commonly known as Tylenol, is not a narcotic; it is classified as a non-opioid analgesic used primarily to relieve pain and reduce fever but does not have the narcotic properties associated with opioids. Ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID), also lacks narcotic characteristics, as it works by reducing inflammation and alleviating pain without any opioid effects. Citalopram is an antidepressant belonging to the selective serotonin reuptake inhibitor (SSRI) class and is not related to pain management or narcotic effects.

Thus, Fentanyl stands out as the correct choice because it is both derived from the opium poppy and classified as a narcotic.