What part covers the crankshaft and holds engine oil?

The crankcase is the correct answer because it serves as the area in the engine that houses the crankshaft and contains engine oil. The crankcase is integral to the lubrication system, ensuring that the crankshaft and other moving parts receive adequate oil to function smoothly and prevent wear and overheating. It is often part of the engine block design, and it plays a vital role in maintaining the engine's oil supply.

While the oil pump is responsible for circulating oil throughout the engine, it does not itself contain oil or the crankshaft. The transmission, on the other hand, is unrelated to the crankshaft's function, as it is focused on transferring power from the engine to the wheels. The engine block is essential in housing the engine's main components, including the cylinders, but the specific term that refers to the space that directly covers the crankshaft while holding oil is the crankcase.