Why Did Militants Take 53 Americans Prisoner from the U

Why did militants take 53 Americans prisoner from the U.S. embassy in Tehran in 1979?

A) The Carter administration had threatened war if the oil embargo was not lifted immediately.
B) The Carter administration had seized a group of insurgents the week before and refused to release them.
C) The Carter administration refused to end American involvement in Nicaragua.
D) President Carter publicly denounced their Ayatollah's revolution.
E) Carter had allowed the exiled shah to seek medical treatment in the United States.