Final answer:
South Africa has the largest proven reserves of strategic metals like manganese, chromium, and platinum, contributing to its wealth and industrial applications.
Step-by-step explanation:
The country that has the largest proven reserves of strategic metals such as manganese, chromium, and platinum is South Africa. South Africa is particularly known for its extensive mineral deposits, including the central gold- and diamond-mining regions. The belt of mineral resources in South Africa also includes significant deposits of platinum, which is critical for various industrial applications. Additionally, diamond mining contributes to the national wealth and increases the standard of living in countries such as Botswana, which neighbors South Africa.