Maple received a land as a gift from her father Billy few years ago. Billy's basis of the land was $12,000 before giving to Maple. The fair market value of the land at the time of gift was $15,000. Maple sold the land for $18,000 this year. What is Maple's gain or loss?

A. A loss of $3,000

B. No gain or loss.

C. A gain of $3,000.

D. A gain of $6,000.