The correct answer is B.
The UN did not describe the conflict in the Darfur Region as a genocide because the explicit instructions given to the military units by the Sudanese goverment appointed to eliminate the rebels, but they did not specify that a specific ethnicity has to be attacked. Anyway, even tough it has not been explicit the UN admits that quite possibly the attacks were intentionally performed against certain sectors of the civilian population.
In any case, the UN acknwledges the seriousness of the crimes committed, considered to be crimes against humanity, but states that the term genocide cannot not be used until each case is investigated and analyzed individually by judicial procedures.