Final answer:
The first country alphabetically among the Sub-Saharan African countries fully or partially south of the Sahara Desert is Angola.
Step-by-step explanation:
According to the U.N., all the countries in Africa that are fully or partially south of the Sahara Desert are "Sub-Saharan" – 46 of the 54 countries on the continent. To list them alphabetically, we start with Angola, followed by Benin, Botswana, Burkina Faso, Burundi, Cabo Verde, Cameroon, Central African Republic, Chad, Comoros, Congo (Brazzaville), Congo (Kinshasa), Cote d'Ivoire, Djibouti, Equatorial Guinea, Eritrea, Eswatini, Ethiopia, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Kenya, Lesotho, Liberia, Madagascar, Malawi, Mali, Mauritania, Mauritius, Mozambique, Namibia, Niger, Nigeria, Rwanda, Sao Tome and Principe, Senegal, Seychelles, Sierra Leone, Somalia, South Africa, South Sudan, Sudan, Tanzania, Togo, Uganda, Zambia, and finally Zimbabwe.