The oil ________ is fastened to the connecting rod cap and picks up oil from the crankcase to lubricate the engine as the crankshaft rotates.

The correct answer is the dipper, which is an integral component used in small engines to ensure proper lubrication. The dipper is specifically designed to be fastened to the connecting rod cap. As the crankshaft rotates, the dipper moves through oil in the crankcase, allowing it to scoop up oil and distribute it to lubricate the engine parts effectively. This mechanism is crucial for maintaining engine performance and longevity since proper lubrication reduces friction and wear on the engine components.

Understanding the role of the dipper highlights its importance in the lubrication system. It is a simple but effective solution for ensuring that the engine internals remain lubricated, particularly in air-cooled two-stroke and some four-stroke engines where gravity-fed systems may not be applicable. Other options, such as a pump or a filter, serve entirely different functions in the engine lubrication process, while a reservoir typically refers to a container for holding oil rather than a component directly involved in the movement of oil during operation.