Which of the Following Are True About the Situation Following

Which of the following are true about the situation following the U.S. invasion of Iraq

A) All of the above
B) Long festering violence between Sunni and Shiite groups was unleashed.
C) Members of al-Qaida members traveled to Iraq to fight the U.S. invaders, but not only engaged in attacks of U.S. troops and coalition supporters, but also Shiites and Sunni groups.
D) A Shiite dominated government was established, but not all Shiites welcomed the U.S. presence.