Concept:A loss of 15% means the selling price is 85% of the cost price.Explanation:Let the cost price be 100.Loss =15% of cost price =15.So, selling price =100−15=85.Thus, ratio of selling price : cost price =85:100.Divide both by 5 to simplify: 17:20.Answer:The ratio of selling price to cost price is 17:20.Correct option: C. 17:20