Concept:Find the cost of one orange, then multiply by the total number of oranges.Explanation:Cost of 3 oranges is GH₵ 0.75.So, cost of 1 orange is 0.75÷3=0.25.Therefore, cost of 90 oranges is 90×0.25.90×0.25=22.50.Thus, the trader received GH₵ 22.50.Answer:A. GH₵ 22.50