The earliest Islamic penetration into sub-Saharan Africa occurred along the east coast, facilitated by Arab traders in the 7th century. This led to the establishment of trade hubs where Islam spread. Therefore, the correct answer is Option B .
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The earliest Islamic penetration of sub-Saharan Africa occurred along the east coast as Arab traders reached East Africa by the 7th century. This led to the spread of Islam in regions like Tanzania and Kenya. The penetration into West Africa happened later, primarily through trade routes. ;