Answer:
A. 30 units of corn and 30 units of wheat
Step-by-step explanation:
If Sylvania dedicates its entire laborforce to the sole production of wheat (because it is most efficient in that) it would produce 60 units of wheat per year (10 workers * 6 units of wheat per year), then it would change 30 units of that wheat for 30 units of Corn with Freedonia.
So it would be abe to consume a maximum of 30 units of corn (traded) and the 30 units of wheat that werent traded.