Answer:
Statements A, B and, C are correct.
Explanation:
Calvin can make decals faster and Hobbs can make chains faster. In other words, we can say that Calvin has a comparative advantage in making decals, while, Hobbs has a comparative advantage in making chains.
This means that Calvin has a low opportunity cost for producing decals and Hobbs has low opportunity cost for producing chains.
The output will be maximized if Calvin makes decals and Hobbs makes chains.
If both divide their time equally between making decals and chains, the output will not be maximized.