Question

Which development led to the other three?

Answer 1

Answer: (4) September 11, 2001 attacks on the United  States. The main reason for the initiation of war in Afghanistan was the September 11 attacks in the year 2001, when the United States was governed by President George W. Bush. The US demanded that Afghanistan should turn in the Taliban supported Al Qaeda head Osama Bin Laden, who was the mastermind behind the 9/11 attacks.

Explanation:

Answer 2

It was the development of the (4) September 11, 2001 attacks on the United
States that led to the development of the other three, which all have to do with security.