Answer:
c. Sectarian violence increased dramatically.
Step-by-step explanation:
The disappearence of a strong center with the demise of the Saddam Hussein´s regime created a power vacuum in Iraq. Sectarian violence and warfare spread throughout the country, many old grievances and conflicts that had been dormant during the Hussein dictatorship resurfaced. One of the main conflicts of post-war Iraq is the clash of Sunnis and Shiias. Shiias are the majority. In this situation, Iran has managed to increase its influence over its neighbor. 16 years after the US-led invasion, Iraq is not a fully stable country.