The correct answer here is A, Mogadishu. Mogadishu is the capital of Somalia. Even though Somalia is not particularly close to Rwanda, the events in Mogadishu did influence Clinton Administration policy in Rwanda.
The deaths of the Americans in Mogadishu helped to illustrate the dangers of having American troops try to intervene in the affairs of other countries. The Americans were there to try to suppress the Somali warlords and thereby help the population of Somalia when they were killed by forces loyal to some warlords. Because of this, the US became very leery of intervening in Rwanda. As the link below tells us,
As events unfolded in Rwanda, American policy makers were strongly influenced by the specter of the Somalia "disaster" of less than a year earlier as they deliberated possible options.
The answer is Mogadishu, which is the largest city and the capital of Somalia. The events in Somalia convinced American policy-makers the dangers of intervening in the affairs of another state. The US was also unwilling to involve themselves in a country, which they had no direct interests in.