Sally was invited to a friend's birthday party. She was also invited to go to the movies with her cousin on the same day. She chooses to go to the movies. What was the opportunity cost of this decision?

A. The movie she goes to see

B. The cost of the movie ticket

C. The enjoyment she may have gotten attending a friend's party

D. The cost of a birthday present

C. The enjoyment she may have gotten attending a friend's party

The opportunity cost of Sally's decision to go to the movies with her cousin is the enjoyment and experience she may have missed out on by not attending her friend's birthday party. This is what she had to give up in order to make the choice to go to the movies.