What are functional requirements in relation to engineering design?

Functional requirements refer to the essential characteristics or capabilities a product must possess to fulfill its intended purpose. These specifications define what a product is supposed to do rather than how it is built or marketed. In engineering design, identifying functional requirements is a crucial step as they establish the foundation for the design process, guiding engineers to ensure that the final product meets the needs of its users and stakeholders.

For instance, if designing a bridge, functional requirements might include the ability to support a specific load, provide safe passage for vehicles, and withstand environmental conditions. Therefore, option B captures the essence of functional requirements perfectly, emphasizing their role in defining the intended functions and purposes of a design. Other choices, while relevant in different contexts, do not specifically relate to the fundamental attributes that determine the operational capabilities of the product.