Sarah wants to watch the 12-hour Lord of the Rings trilogy on Netflix. When is the opportunity cost of her time higher, before or after the exams?

A) The opportunity cost of her time is higher before the exams.

B) The opportunity cost of her time is higher after the exams.

C) The opportunity cost of her time is the same before or after the exams, because the length of the Lord of the Rings trilogy (12 hours) is unchanged no matter when Sarah watches it.

D) We are not sure unless we know the cost of Sarah's Netflix subscription.