The three land-locked countries in West Africa are Mali, Burkina Faso, and Niger.
A landlocked country is a nation that does not have direct access to the sea or any oceans. In West Africa, Mali, Burkina Faso, and Niger are all countries that do not have a coastline. They are surrounded by other countries on all sides and do not have a direct connection to any sea or ocean.
In contrast, the other options listed include countries that do have a coastline or access to the sea. For example, the Republic of Benin has a coastline along the Gulf of Guinea, while Togo and Ghana both have coastlines along the Atlantic Ocean. Mauritania has a coastline along the Atlantic Ocean, but it is mostly considered a desert country. Chad is a landlocked country, but it is not in West Africa, and Senegal has a coastline along the Atlantic Ocean.