What aspect of design deals specifically with the human scale and ergonomics?

The correct answer focuses on Space Planning, which directly relates to the human scale and ergonomics in design. Space planning involves organizing and designing the layout of spaces with careful consideration for how people will interact with those environments. This includes not only the physical dimensions of spaces but also how they accommodate human activities, comfort, and movement.

Ergonomics is a crucial aspect of space planning as it aims to create environments that optimize well-being and performance by fitting the design to the human body and its cognitive abilities. By addressing the needs of users, designers ensure that spaces are functional and promote efficient use.

Options that focus on schematic design, interior architecture, and furniture design address different aspects of design. Schematic design pertains more to the overarching vision and conceptual layout of a project rather than the specifics of human interaction. Interior architecture deals with the aesthetic and functional design of interior spaces but does not focus specifically on user-centered dimensions as strongly as space planning does. Furniture design concentrates on the creation of individual pieces of furniture, considering ergonomics but typically within the context of a larger space rather than as the sole focus.

Thus, Space Planning is uniquely positioned at the intersection of design and human needs, making it the right answer in the context of the question.