Comment: Somewhere between A and

Somewhere between A and B.
The only reason I don't say A is that I'm not sure it counts as an "inside job" if the government found out about it and allowed it to happen. I'm not sure exactly who carried out the act, but I feel pretty safe in concluding that the buildings were brought down by controlled demolitions. I learned about this in 2007 during the presidential primary season, and the evidence has only gotten stronger over time. There are various theories out there, and I can't really pick one for certain, but I can tell you that the official 9/11 commission version is not true.

I think this is the best video to introduce someone to the topic, or just to sum up everything in 15 min.
http://www.youtube.com/watch?v=hZEvA8BCoBw

This is a nice scientific documentary with Steven Jones from BYU explaining what he found in the World Trade Center dust if you want to add another 45 min of video:
http://www.youtube.com/watch?v=8cfjYUHF8UE