Final answer:
a. Swahili has the largest number of native speakers among the African languages listed, serving as a lingua franca in many parts of East Africa.
Step-by-step explanation:
Of the African languages mentioned, a. Swahili has the largest number of native speakers. Swahili is not only spoken in Tanzania but also serves as a second language throughout much of East Africa. It acts as a significant cultural link amidst various ethnic groups.
In Tanzania, Swahili serves as the lingua franca and is given preference over English, which is only used in certain formal contexts like higher legal courts and universities. Across Africa, Bantu languages, including Swahili, are widely spoken as a result of the Bantu migration.