Which of the following is a medicine that induces nausea and vomiting?

The correct answer is a term commonly used in medical contexts to describe a specific class of medication or substance that induces nausea and vomiting. This term comes from the root "nausea," which directly relates to the feeling of being sick and leads to vomiting. Nauseants are used in specific medical situations, often to empty the stomach or to induce vomiting for various therapeutic reasons, such as in cases of poisoning.

The other terms are not related to the induction of nausea or vomiting. Narcissism refers to a psychological condition involving self-centeredness and a lack of empathy and has no connection to the effects of nausea. Neuritis refers to the inflammation of a nerve and is associated with pain and nerve dysfunction, not gastrointestinal symptoms. Neuralgia describes intense pain along the path of a nerve without involving the sensation of nausea or vomiting.