What must be present when a wall faces an unoccupied area concerning access and location?

When a wall faces an unoccupied area, having all conditions met is crucial for compliance with safety and building codes. The requirement for access and location ensures that the area can be maintained and accessed safely, addresses potential fire safety issues, and considers the provisions for emergency services. Having access from a street ensures that there are routes available not only for maintenance purposes but also for potential emergency services that might need to reach the area quickly.

The stipulation for the wall to be near a certain size or the requirement for the wall to be on the same lot pertains to ensuring that the structure adheres to zoning laws and building codes related to setbacks and spacing. Meeting all of these conditions guarantees that the space is both functional and regulatory compliant, thus making option D the correct response.