What is the primary purpose of pulling the firewall shutoff handle?

The primary purpose of pulling the firewall shutoff handle is to isolate systems during emergencies. This action is crucial in situations where a fire or fuel leak occurs in the engine compartment. By pulling the handle, the pilot can stop the flow of fuel to the engine or an affected area, which is essential for mitigating the risk of fire and ensuring the safety of the crew and passengers. Isolating systems helps to prevent the situation from escalating and allows for emergency procedures to be initiated, enhancing safety in critical scenarios.

While other options mention functions like gaining altitude or regulating fuel flow, these choices do not address the specific emergency response aspect of pulling the shutoff handle. Maintaining gear functionality is also unrelated, as this action is focused purely on fuel system isolation, making it clear that option focusing on emergency system isolation is the correct answer.