Final answer:
If Shawn can produce donuts at a lower opportunity cost than Sue, it means Shawn has a comparative advantage in producing donuts. This is because Shawn gives up less than Sue to produce donuts, which makes him more efficient in their production.
Step-by-step explanation:
If Shawn can produce donuts at a lower opportunity cost than Sue, then what can be concluded is that Shawn has a comparative advantage in producing donuts. Opportunity cost is the next best alternative given up when making a choice. Therefore, the correct conclusion is that Shawn is more efficient than Sue in producing donuts, because he gives up less of other goods to make donuts. We can compare this to Maria and Charlie, who work at a coffee shop. Maria's opportunity cost for 1 latte is fewer sandwiches compared to what Charlie gives up; similarly, Plant 3 has a comparative advantage in producing snowboards because the opportunity costs of producing snowboards there is the lowest among the plants. Consequently, Shawn does not necessarily have to produce more donuts than Sue to have a comparative advantage; he simply needs to have the lowest opportunity cost for producing them, which indicates he should specialize in donut production.