Hi Hannah,
I think what is causing you trouble here is that fact that at times and individual may be under conflicting pressure or expectations from different groups of people. It is true that there may be peer pressure for students to attend parties, and conforming with peers would mean going to party instead of studying, however society at large would have a different perspective. Generally, going to a party instead of studying, particularly if one has a big assignment or exam coming up, would be seen as irresponsible or hedonistic. The "right" thing to do is to stay home. It is very similar to the answer question B, skipping work to go to a concert. Both involve a responsibility and an opportunity have fun, but option A forgoes the fun to be responsible, making it an expression of the 'Me.'

Nicole