Which of the following can be misused by minors, often resulting in euphoria?

Dextromethorphan is a medication commonly found in over-the-counter cough and cold preparations. It acts as a cough suppressant but, when misused, can lead to dissociative and euphoric effects. This misuse is particularly prevalent among minors seeking to experience these euphoric effects, often due to its accessibility and the fact that it is legal and available without a prescription in many places.

In contrast to dextromethorphan, the other options listed, such as aspirin, benzonatate, and ibuprofen, do not produce euphoric effects when taken in the manner intended or even when misused. Aspirin is primarily used for pain relief and reducing inflammation, benzonatate is a prescription cough suppressant that works locally in the lungs, and ibuprofen is also an anti-inflammatory and pain-relieving medication. These substances lack the psychoactive properties that lead to the euphoric experiences associated with dextromethorphan misuse. Thus, dextromethorphan stands out as the drug that can be misused by minors to achieve euphoria, making it the correct choice for this question.