A nurse is caring for a client who has cancer and reports moderate pain. Which of the following medications should the nurse expect to administer?

The correct answer is A: Morphine. Morphine is a potent opioid analgesic commonly used for moderate to severe cancer pain due to its strong pain-relieving properties. It works by binding to opioid receptors in the brain and spinal cord, altering the perception of pain. Acetaminophen (B) is a mild pain reliever and is not typically sufficient for moderate cancer pain. Ibuprofen (C) and Aspirin (D) are nonsteroidal anti-inflammatory drugs (NSAIDs) that are not as effective as opioids for moderate to severe cancer pain. They also carry a higher risk of gastrointestinal side effects which may not be ideal for cancer patients.