Which one of the following statements is incorrect?

The exploitation of natural resources played an important role in the development of the South African economy.
The quality of the South African labour force leaves a great deal to be desired.
South Africa is a capital-rich country, which exports large quantities of capital goods to the rest of the world.
Exports of minerals and metals have played a key role in the growth of the South African economy.

South Africa is a capital-rich country, which exports large quantities of capital goods to the rest of the world.