I belive that the answer is D. because a Sahel is not A. "an African territory of historical importance". It is not B. "a landform found only in Africa, it is a cross between a mountain and a plateau" It is not C. "a climatic event with high winds and heavy rains". But it is correct that it is "a wide area of dry land located along the southern edge of the Sahara". which makes it D.