Which EPEAT criteria require manufacturers to enhance the upgradeability of their products?

The correct answer is rooted in the idea of extending the useful life of a product. The criteria focused on Product Longevity / Life Cycle Extension specifically emphasize designing products with the capability for upgrades, improvements, and serviceability. This ensures that devices can remain relevant and functional longer, reducing the need for outright replacement. By enhancing the upgradeability of products, manufacturers can support sustainability goals, as users can keep their devices up to date with new technologies without discarding them prematurely.

This contrasts with the other aspects listed in the choices. Energy Efficiency pertains to how effectively a product uses energy during its lifetime. Recyclability focuses on the end-of-life process, determining how materials can be repurposed after a product is no longer in use. Hazardous Substance Reduction deals with minimizing toxic materials in the manufacturing process. Each of these criteria plays a role in environmental sustainability, but they do not directly relate to the upgradeability of products the way Product Longevity / Life Cycle Extension does.