What is the purpose of an accessory gearbox in an aircraft engine?

The accessory gearbox serves a crucial role in an aircraft engine by providing power to engine accessories. These accessories may include components such as the fuel pump, oil pump, alternator, and other systems that are essential for the engine's operation and overall functionality.

The gearbox integrates with the engine, allowing it to mechanically drive these accessories, typically by harnessing the rotational energy produced by the engine itself. This design ensures that the accessories operate efficiently and effectively, maintaining the performance of the engine and ensuring safety during flight operations.

In contrast, increasing fuel pressure, cooling engine components, and filtering engine oil are handled by other systems and components within the aircraft's engine architecture. Therefore, the primary function of the accessory gearbox is to act as a power distributor for the various necessary accessories, making this choice the most accurate in relation to the purpose outlined in the question.