The engine fire warning system monitors which of the following?

The engine fire warning system is specifically designed to monitor temperatures that may indicate the presence of a fire in the engine compartment. It primarily focuses on average and discrete engine exterior temperatures. These measurements are crucial because a sudden spike in temperature can signal a fire or impending failure, prompting immediate action by the pilot.

Average exterior temperatures provide a broad overview of the engine's thermal state, while discrete temperatures allow for more precise identification of hot spots, which could indicate localized overheating or potential fire conditions. This dual approach helps ensure the engine operates within safe limits and alerts the pilot to any threats that may arise from abnormal temperature readings.

In contrast, options that include engine oil temperature may not be relevant to the specific function of the fire warning system, which is focused solely on monitoring the external temperatures associated with fire risk, rather than the performance or health indicators of engine lubrication. This distinction is important for understanding the specific role of the engine fire warning system in maintaining flight safety.