Final answer:
A human factors psychologist would be concerned about specific features of horizontal, vertical, and flat work surfaces within a work space.
Step-by-step explanation:
A human factors psychologist would be concerned about specific features of horizontal, vertical, and flat work surfaces within the three-dimensional envelope of a work space. These specific features include factors such as the height of the chair, the positioning of the work surface, and the ergonomics of the workspace. By considering these factors, a human factors psychologist aims to create a work environment that promotes productivity, comfort, and overall well-being.