An investor is looking at two properties, but will only purchase one of them. Each is similar in utility and location, and has an annual net operating income of $20,000. One has a listing price of $220,000, while the other is listed at $200,000. The investor purchases the $200,000 property. Which economic principle is demonstrated in this example?
A. Regression
B. Externalities
C. Substitution
D. Contribution