Assume George and Abe are stranded on an island and can only produce two goods: fish and coconuts. George can catch 20 fish or collect 5 coconuts in one day and Abe can catch 15 fish or collect 3 coconuts in one day. What is Abe's opportunity cost of catching 1 fish? a. 1/3 of a coccnut b. 3 coconuts c. 5 coconuts d. 1/5 of a coconut