High-school athletes who skip college to become professional athletes a. obviously do not understand the value of a college education. b. usually do so because they cannot get into college. c. understand that the opportunity cost of attending college is very high. d. are not making a rational decision since the marginal benefits of college outweigh the marginal costs of college for high-school athletes.

The correct answer is letter "C": understand that the opportunity cost of attending college is very high.

Explanation:

Opportunity cost refers to the return of choosing one option compared to the best next available choice. In other words, an opportunity cost represents what is left on the table after taking one decision and discarding others. In the example, high-school athletes who skip college to pursue a professional athlete career must understand that the opportunity cost of attending college is high. However, the benefits of becoming a prominent professional could be even higher.

An example of this is Los Angeles Lakers American basketball player Lebron James (born in 1984) who does not hold a bachelor's degree but is considered one of the best basketball players of history. James earns an approximate of $37.4 million annually only in his salary which is above what regularly certified professionals can receive per year.