The cost of educating a college student

a. Is less than the cost of educating a high school student because college classes are generally large.

b. Is equal to the cost of educating a high school student because,although college teachers make more money, their classes are generally larger.

c. Is less than it used to be.

d. Is much greater than the cost of educating a high school student because college professors make more money and teach fewer hours per week.