This country has faced severe ethnic violence in its Darfur region. In 2011, the country held an election and voted to split into two separate countries. Which country is described in the passage above?

In order to answer this question, you only need to know in which country does the Darfur region lie - and the answer is Sudan. This is also the correct answer to this question

The two countries that Sudan split into are Sudan and South Sudan. (South Sudan has been very unstable since the separation).