Answer:
b. Rob has a comparative advantage in catching fish.
Step-by-step explanation:
Rob has an absolute advantage in catching fish since he can catch more fish than Bill in the same amount of time.
Neither have an absolute advantage on picking berries, since they both picked the same amount.
The opportunity cost of picking a berry for Rob and Bill are, respectively:
Bill has a lower opportunity cost for picking berries than Rob and, therefore, Bill has a comparative advantage in picking berries.
The opportunity cost of catching a fish for Rob and Bill are, respectively:
Rob has a lower opportunity cost for fishing than Bill and, therefore, Rob has a comparative advantage in catching fish.
The only option that fits the data is b. Rob has a comparative advantage in catching fish.