Which of the following indicates low oil pressure in the F/A-18 E/F?

The indication of low oil pressure in the F/A-18 E/F is primarily represented by warning lights and gauge readings. These instruments provide real-time feedback on the engine's operating conditions. The engine oil pressure gauge monitors the pressure of the oil circulating within the engine and will show a drop in pressure if it falls below the normal operational range. Concurrently, the engine monitoring systems will activate warning lights to alert the pilot and ground crew to the abnormal condition, which is crucial for timely intervention to prevent potential engine damage.

In contrast, while engine rumbling noise can be a symptom of many issues including low oil pressure, it is not a definitive indicator and can arise from other sources of noise unrelated to oil pressure. Increased fuel consumption can reflect several engine performance problems, but it does not directly indicate low oil pressure. Sudden loss of altitude is more typically associated with aerodynamic issues or engine failure, rather than oil pressure, and does not provide direct information about oil system health. Thus, relying on the warning lights and gauge readings is the most accurate method for identifying low oil pressure in the aircraft.