On the 19th March 2003, the US launched its invasion of Iraq under the code name:

Operation Iraqi Freedom

*The correct answer is option (4) - Operation Iraqi Freedom*

On 19 March 2003, the US launched its invasion of Iraq under the codename ‘Operation Iraqi Freedom’. More than forty other countries joined in the US-led ‘coalition of the willing’ after the UN refused to give its mandate to the invasion. The ostensible purpose of the invasion was to prevent Iraq from developing weapons of mass destruction (WMD). Since no evidence of WMD has been unearthed in Iraq, it is speculated that the invasion was motivated by other objectives, such as controlling Iraqi oilfields and installing a regime friendly to the US.