What terrorist group was responsible for the attacks of september 11

Al Qaeda

Explanation:

Al Qaeda is the terrorist group responsible for the September 11 attacks on the world trade center in United states.

The leader of this group then was Osama bin Laden then before he was killed May 1 2011 by United states forces.

The current leader is Ayman al-Zawahiri  who became the leader june 2011.

there are no options provided but you can choose among the following gender-neutral pronouns: zir, hir, eir, vis, tem, eir.

in the normal course of maintaining a pronoun-antecedent agreement, we could have used the words his or her but since we are also required to use gender-neutral language, we need to replace it with its equivalent gender-neutral pronoun.