which answer is correct?

Mario divides his time between fishing and farming In one day he can catch 20 kilograms of fish or harvest 10 bushels of potatoes, Mario's opportunity cost of farming is 2 Halograms fish per bushel of potatoes 2 bushels potatoes per Kilogram of fish 1/2 bushel potatoes per kilogram of fish 2 potatoes per fish. 1/2 Hologram bich per bushel of potatoes