I need the choices; but basically Al Qaeda is a terrorist group responsible for 9/11. So they are honestly the reason that we have to go through so much security when we go on airplanes. It's also the reason we have 9/11 as a holiday and have a memorial museum dedicated to that unfortunate day. If you told me the choices I could help though!
Explanation:
Red Guards, in Chinese history, groups of militant university and high school students formed into paramilitary units as part of the Cultural Revolution (1966–76). These young people often wore green jackets similar to the uniforms of the Chinese army at the time, with red armbands attached to one.
