The Bosnian-Herzegovina conflict during the 1990s was primarily driven by B) ethnic tensions and nationalist aspirations within Bosnia-Herzegovina.
While the other factors you mentioned, such as A) ideological clashes and D) economic inequality, may have played some role in the broader context of the Yugoslav Wars, the core issue in Bosnia-Herzegovina was the complex interplay of ethnic identities (primarily between Bosniaks, Croats, and Serbs) and the desire for self-determination and national recognition.
C) Territorial disputes between neighboring countries did occur, especially considering the breakup of Yugoslavia, but the central conflict stemmed significantly from internal ethnic issues rather than simply external territorial ambitions.