If you receive a free ticket to a​ concert, what, if​ anything, is your opportunity cost of attending the​ concert?
a. the pleasure yielded by the concert cancels any costs.​ thus, there is no cost of any type.
b. since the ticket was a​ gift, there is no opportunity cost.
c. the next best activity that​ can't be done while attending the concert.
d. the concept of opportunity cost does not apply to intangibles like concerts.