When should you NOT make a person vomit after swallowing poison?

The correct answer is based on the critical understanding of the risks associated with inducing vomiting after the ingestion of certain types of poisons. When an individual has swallowed corrosive substances, such as strong acids or bases, inducing vomiting can cause additional harm. This is because the act of vomiting can bring the corrosive material back up through the esophagus and into the mouth, potentially causing further burning or damage to the tissues in those areas.

Corrosive substances can severely irritate or burn the lining of the gastrointestinal tract, and forcing the body to expel these substances increases the risk of more serious injuries. Therefore, in cases of corrosive ingestion, it is crucial to seek immediate medical attention rather than attempting to induce vomiting.

The other options do not present the same level of risk associated with inducing vomiting. Being conscious and breathing normally may be assessed as stable conditions, while having not ingested anything means inducing vomiting is unnecessary.