Which of the following is NOT a firefighter's primary responsibility?

Firefighters are primarily focused on tasks that directly enhance public safety and emergency response. Their core duties include extinguishing fires, conducting rescue operations, and providing education on fire safety to prevent incidents from occurring in the first place.

Investing in fire-related businesses does not fall under the responsibilities of a firefighter. Firefighters are dedicated to active roles in mitigating fire hazards, responding to emergencies, and educating the public about fire prevention and safety strategies. Their primary mission revolves around saving lives and protecting property, making any involvement in business investments outside their critical job functions. Hence, this choice distinctly does not align with the fundamental duties of a firefighter.