Concept:Sierra Leone has one of the wettest coastal climates in West Africa.Explanation:The coastal regions lie directly in the path of the moist south-west monsoon winds.These winds bring heavy and prolonged rainfall, especially during the rainy season.The coastal relief also forces the moist air upward, increasing rainfall totals.As a result, the annual rainfall in this coastal belt is over 4,800mm.This high rainfall makes Sierra Leone the wettest country in West Africa.Answer:C. 4,800mm