The correct answer would be the third option. The international agency that launched investigations into the human genocide in Darfur is the International Criminal Court or ICC. As the case is involved with human genocide or killing of a large group of people, it would be under the category of murder. So, it would be the International Criminal Court that would be handling this case. The ICC is an international tribunal that has the power to prosecute people for crimes like genocide, war crimes and crimes pertaining to humanity. The headquarters for this agency is found in The Hague in the country of Netherlands.
