Answer: B) Despite quick success of the invasion, a difficult occupation, fueled by a fierce insurgency, followed.
Step-by-step explanation:
The United States led a coalition of countries to invade Iraq in 2003 due to a belief that the Iraqi leader, Saddam Hussein was hoarding weapons of mass destruction.
The invasion and defeat of the Iraqi forces took less than a month and so was quickly successful. The hard part however, came afterwards as the U.S. faced a difficult occupation and a fierce insurgency that lasted until the defeat of Islamic State in 2017.