Which is the official language of Southern African Development Community :

English, French
Portuguese
German
A and B

The official languages of the Southern African Development Community (SADC) are English and Portuguese.

English is the most widely spoken language in SADC, with over 100 million speakers. It is the official language of Botswana, Lesotho, Malawi, Mozambique, Namibia, South Africa, Swaziland, Zambia, and Zimbabwe.

Portuguese is the official language of Angola, Mozambique, and São Tomé and Príncipe. It is also spoken by a significant minority in South Africa.

The other options are incorrect. French is not an official language of SADC. German is spoken by a small minority in Namibia, but it is not an official language.