Which is not an underlying assumption of a theoretical model of costs and health outcomes?

Which is not an underlying assumption of a theoretical model of costs and health outcomes?
A . The relevant outcome is the overall health of a population rather than of an individual.
B. It is possible to quantify health at a population level.
C. It is necessary to focus on health outcomes, those aspects of health status directly under the influence of health care.
D. It is impossible to reduce cost without also reducing health outcomes.

Answer: D