Question

What significance did weapons of mass destruction have in the U.S. invasion of Iraq?

Weapons of mass destruction played no part in the U.S. invasion of Iraq.
So many weapons of mass destruction were discovered in Iraq that it took longer than anticipated to locate all of them.
President Bush threatened to use weapons of mass destruction if the air attack was unsuccessful.
President Bush said that weapons of mass destruction existed there, but that proved not the case.

Answer 1

Last one for now, @Shadow
I think it's D

Answer 2

https://en.wikipedia.org/wiki/Rationale_for_the_Iraq_War

Answer 3

Don't know this one, you'll have to research (:

Answer 4

I was right ^_^