The adverb clause in this sentence is 'before class starts', and it modifies 'meet', so A is the correct answer.
B, C and F I believe... please correct me if I'm wrong, though ^^
I think he argues that school is not a platform for free speech?
I believe the answer is D.
The guest are happy that they are able to wall off themselves from the world containing the Red Death. They planned to live and dance in luxury until disease died out. The only thing halting their excitement was the ominous clock chimes where all would stop until it ended.