Which institution does not receive legal deposits in South Africa?

The question asks which institution does not receive legal deposits. Legal deposit institutions are designated by law to receive copies of all published materials for preservation. In South Africa, these are primarily national institutions.

• A. National Film Video and Sound Archives is a legal deposit institution for audio-visual materials.
• B. National Library of South Africa is the primary legal deposit institution for print materials.
• C. Mangaung Libraries (Bloemfontein) is a public library system. Public libraries are not designated as legal deposit institutions.
• D. University of South Africa Library Services is an academic library. Academic libraries are generally not designated as legal deposit institutions for national publications.

Both C and D do not receive legal deposits under the Legal Deposit Act, 1997. However, in multiple-choice questions, there is usually one best answer. Public libraries (like Mangaung Libraries) are fundamentally local service providers and are unequivocally not legal deposit institutions.

The correct option is C.

The final answer is $\boxed{\text{C}}$