Oil control rings are made:

Oil control rings play a crucial role in the functionality of an engine by regulating the flow of oil to the cylinder walls, ensuring not too much oil enters the combustion chamber while also maintaining appropriate lubrication on the cylinder. These rings are essential for preventing excessive oil consumption and minimizing emissions.

The correct response indicates that oil control rings are manufactured in either one or three pieces. This versatility allows for different designs and configurations to suit various engine types and performance requirements. Single-piece oil rings are typically simpler and adequate for many standard applications. In contrast, three-piece oil rings usually consist of two narrow outer rings and a thicker inner expander. This configuration can provide better control of oil and improved sealing under different operating conditions.

The option stating that oil control rings are made only in one piece or only in three pieces would limit the understanding and applicability of the rings in various engine designs. Additionally, the idea that they can be made in any number of pieces is overly broad and not practical, as oil control rings are designed with specific configurations that have proven effective in real-world applications. Thus, the recognition that these rings can be produced in either one or three pieces reflects the engineering advancements and choices available in small engine design.