Suppose You Bought Three Tickets to a Concert in Advance

Suppose you bought three tickets to a concert in advance at the University ticket window. At the last minute one friend cancelled, so you could use only two of the tickets. You sold the third ticket just outside the entrance to the concert for more than the price you had originally paid. Which transaction occurred in a market?

A) The advance purchase at the University was the only market transaction.
B) The sale that occurred at the concert entrance was the only market transaction.
C) Both the purchase at the University ticket window and the sale at the concert entrance were market transactions.
D) Neither the purchase at the University ticket window nor the sale at the concert entrance was a market transaction.