The question says, 'slum areas, usually called Ashanty towns exist in ................... major African cities, housing .................. percent of urban population. The correct option is B. Slum areas occur in almost all the major African countries, the biggest one in the world is found in Cape town, South Africa. The majority of the slum dwellers are between age 15 and 24. Africans are making efforts to reduce slum areas.