Concept:Ghana's main manganese mine is at Nsuta, near Tarkwa in the Western Region.Solution:Nsuta has been mined for manganese since the 1910s and is Ghana's main source of the mineral.Nkwatia and Mpraeso are towns on the Kwahu Plateau, known for trade, not manganese.Saltpond is a coastal town in the Central Region, known for fishing and an offshore oil field.So the manganese producing centre is Nsuta.Answer:Option B (Nsuta)