Jurassic Park sells only one product, plastic dinosaurs, at a regular price of $36.90 per unit. Variable expenses are 58% of sales and fixed expenses are $62,000. Management has decided to decrease the selling price to $31.05 in hopes of increasing its volume of sales. What is the contribution margin ratio when the selling price is reduced to $31.05 per unit?

a) 42%

b) 31.1%

c) 58%

d) 68.9%

(Please show/explain you entire process)