Read this: The southwest of the country is a coastal plain for which the primary drainage is the Kouilou-Niari River; the interior of the country consists of a central plateau between two basins to the south and north. Forests are under increasing exploitation pressure.

Which river serves as drainage for the southwest plain of the Congo?
What is the answer? (If it cannot be answered, return "unanswerable")
Kouilou-Niari River