Correct option is A
Non-functional dimensions are those dimensions in a drawing that do not directly affect the working or performance of a component. They are mainly provided for manufacturing convenience, aesthetics, or reference purposes, rather than for ensuring proper fit or operation. For example, the overall length of a decorative cover or spacing between non-critical features may be considered non-functional.
In contrast, functional dimensions are critical for assembly, performance, and interchangeability, such as shaft diameter or hole size. Options c and d refer to derived dimensions, which is a different concept related to dimensioning methods, not functionality.
