http://7sage.com/lsat_explanations/lsat-71-section-3-question-21/
I've figured out why C) and E) are wrong, but I'm not sure how the other incorrect answers weaken the argument.
Fire Alarm went off during Section 3 (not experimental) in room and all of building. Extremely loud and lasted for over 5 minutes and less than 10 minutes (exam continued normally). This definitely adversely affected me.