Which theory utilizes math, formulae, and a lo p'an to assess chi flow?

The correct choice relates to the Compass Theory, which is a method often used in traditional Chinese practices, particularly in feng shui. This theory employs mathematical principles and specific calculations along with a lo p'an, a specialized compass used in feng shui assessments. The lo p'an assists practitioners in determining auspicious orientations and the flow of chi, or energy, in a given space or environment. By using mathematical calculations in conjunction with this compass, practitioners can analyze how different elements within an environment interact with each other and influence the flow of energy.

In contrast, the other theories listed do not focus on the same unique blend of mathematical assessment and orientation tools. Environmental theory might examine the broader impacts of surroundings on human behavior but lacks the specific application of a lo p'an. Form theory generally concerns the shapes and forms in design but does not integrate the same analytical components found in the Compass Theory. Geometric theory might involve the mathematical aspects of design and space but does not specifically use the principles of feng shui or the lo p'an for assessing energy flow. Thus, the distinct emphasis on chi flow assessment through mathematical tools in combination with a lo p'an is what substantively identifies the Compass Theory as the correct answer.