Globalization increased international contact allows diseases to spread farther and faster.
I believe the answer is D. Stopping all transportation
The 9/11 assaults were completed by 19 obsessive Muslims following up on the requests of Osama container Laden, the organizer and pioneer of al-Qaeda, who was being given asylum by the Taliban administration in Afghanistan; and the intrusion ended up plainly essential when they obstinately declined to turn him over to U.S. specialists.
Do you have a specific civilization you are asking about? Or are we just implying on what we think makes best for a beginning of one?