If I were high up in the Deep State, and wanted such a disaster to take place to justify my wars... I would choose "all of the above".

The buildings would be prepped in advance, explosive charges set AND planes would be "hijacked" and slam into those buildings as the explosives are remotely detonated. Why take chances?

Airplanes are too unpredictable. It's possible they may graze a building or hit wrong, so the damage would be minimized. No way!!! Not on my watch. If the airplane even makes casual contact, the explosives would detonate and take down the building at that moment. I would also set high temperature thermal charges on main columns to ensure the things collapsed.

People think it was was EITHER the planes (therefor,a terrorist attack) or a preset explosive (therefore, false flag). Why can't BOTH be true? Pre-planned "terrorist attack (R.I.P. passengers) and old-fashioned demolition.