Final answer:
The opportunity cost of spending a night with friends includes all potential alternatives given up by making that choice, encompassing movies, sleep, and study time.
Step-by-step explanation:
The opportunity cost of spending a night with friends includes anything else that you could have done with that time, which has value to you. In this scenario, the opportunity cost could be 'the movie I could have seen,' 'the several hours of sleep I could have had,' or 'the better grade I could have earned with more study.' Thus, the correct answer is All of the above, as opportunity cost encompasses all potential alternatives forgone by making a particular choice, and in the described situation, each option presents a valid alternative that was sacrificed.