What should be the first priority during a hazardous materials incident?

Answer: C — Rescue of victims.

During a hazardous materials incident, the rescue of victims is the first priority. The safety and life of individuals at the scene are paramount, as they may be in immediate danger from exposure to harmful substances or the effects of the incident itself. First responders are trained to assess the situation quickly, ensuring any individuals in harm's way are evacuated or assisted to safety as swiftly as possible. While actions such as controlling spills, protecting the environment, and maintaining clear access for emergency services are important and will follow in the response plan, they cannot take precedence over the immediate need to save lives. The focus on victim rescue ensures that any people affected by the incident receive prompt medical attention and that further harm is mitigated.