Which of the following best describes a landfill?

A landfill is primarily recognized as a site for the disposal of waste materials. This means that its primary function is to provide a designated area where waste can be safely deposited and contained. While landfills may have additional features or functions, such as capturing gas emissions or leachate management, their central role is to serve as a final resting place for various types of waste.

The other options relate to processes or facilities that handle waste in different ways. Resource recovery, the processing of recyclables, and waste-to-energy conversion are distinct activities that aim to minimize waste or convert it into usable resources or energy, but they do not define what a landfill is at its core. A landfill specifically focuses on the containment of waste, differentiating its role from these other waste management practices.