The correct answer is C. Italy.
Step-by-step explanation
Before the First World War, Germany had the initiative to form the Triple Alliance to get support in case of being attacked by France or Russia (the most threatening countries towards German territory). The countries that formed this alliance were the Austro Hungarian Empire, and Italy, however, at the beginning of the First World War some circumstances caused Italy to abandon this alliance and move to the opposite side, including the territorial dispute with the Austro Hungarian empire in the region of the Trentino, also, Germany did not support the Italian interests on the North of Africa. So, the correct answer is C. Italy.