Alex Received a Four-Year Scholarship to State U

Alex received a four-year scholarship to State U. that covered tuition and fees, room and board, and books and supplies. As a result:

A) attending State U. for four years is costless for Alex.
B) Alex has no incentive to work hard while at State U.
C) the cost of attending State U. is the amount of money Alex could have earned working for four years.
D) the cost of attending State U. is the sum of the benefits Alex would have had attending each of the four other schools to which Alex had been admitted.