Concept:Savanna zones receive less rainfall, so crops that grow well in drier conditions are most suitable for these areas.
Explanation:Cotton, millet, and groundnut are common savanna crops because they require only moderate rainfall and can grow in well-drained soils.
These crops are hardy and survive the long dry season typical of West African savanna zones.
On the other hand, cocoa, kola, oil palm, rubber, and banana are forest crops that need heavy rainfall and high humidity, which are not available in the savanna.
Guinea corn is indeed a savanna crop, but option C includes cocoa, which is a forest crop, so option C is wrong.
Similarly, option D contains banana and rubber, which cannot grow best in the savanna.
Thus, the only complete group of crops suited to the savanna is cotton, millet, and groundnut.
Answer:A. cotton, millet and groundnut