The answer is A. But why? Please do not give my 9 cause it is wrong.

24.5 In Problem 24.13, in the absence of government interference, there is a constant marginal cost of $5 per ounce for growing marijuana and delivering it to buyers. If the probability that any shipment of marijuana is seized is .20 and the fine if a shipper is caught is $20 per ounce, then the equilibrium price of marijuana per ounce is (a) $11.25. (b) $9. (c) $25. (d) $4. (e) $6