Melody decides to spend three hours at the park with her friends rather than working overtime. She earns $20 per hour for overtime work. Her opportunity cost of going to the park is

A) The $60 she could earn working.

B) The enjoyment she would have received had she gone to the park

C) The $60 minus the enjoyment she would have received from going to the park.

D) Nothing, since she would have received less than $60 worth of enjoyment from going to the park.