Answer: A. The island of Atlantis has an increasing opportunity cost of producing potatoes and the production possibility frontier is bowed outward.
Explanation:
When there is an increasing opportunity cost of producing a good, the Production Possibilities Frontier (PPF) will be bowed out to represent that as more of the good is being produced, more of another good is being given up to do so.
For the island of Atlantis therefore, as they produce more of potatoes, they are giving up being able to produce whatever more and more of other goods they produce which is therefore leading to a PPF that is bowed outward.