Which 19-country common market is focused on Eastern and Southern Africa?

COMESA, or the Common Market for Eastern and Southern Africa, is indeed focused on promoting economic integration among countries in Eastern and Southern Africa. It was established to create a large market that enhances trade and investment opportunities within the member states. The organization aims to strengthen the economic position of its members by developing a common market, facilitating the free movement of goods, services, people, and capital among its member countries.

The other choices pertain to different regions or types of economic agreements. The European Union primarily addresses European member nations and encompasses a broad range of economic and political cooperation. NAFTA, now replaced by the USMCA, was an agreement among North American countries (the United States, Canada, and Mexico) to promote trade and economic cooperation. The ANC (African National Congress) is a political party in South Africa and not an economic union or common market. Thus, the identification of COMESA as a 19-country common market relevant to Eastern and Southern Africa is accurate and reflects its primary purpose and scope.