To which of these countries did Nigeria send peacekeeping force?

Nigeria sent peacekeeping forces to several countries, but the question asks for only one of them. Therefore, the answer is: Nigeria sent peacekeeping forces to Chad. Chad is a neighboring country to Nigeria and the peacekeeping mission was in response to the Chadian-Libyan conflict in the 1980s. Nigeria led the multinational force that included troops from other African countries such as Senegal, Sudan, and Egypt. The mission was to prevent the conflict from spilling over to other countries in the region and to ensure stability in Chad. The peacekeeping mission was considered a success, and Nigeria received praise for its leadership and contribution to peacekeeping efforts in Africa.