Question

Suppose Canada produces only smartphones and tablets. The resources that are used in the production of these two goods are not specialized—that is, the same set of resources is equally useful in producing both tablets and smartphones.
The shape of Canada’s production possibilities frontier (PPF) should reflect the fact that as Canada produces more tablets and fewer smartphones, the opportunity cost of producing each additional tablet ____? (decrease, increase, constant)

Answer 1

I think the opportunity cost would be increased.

It's stated that the resources to make the two products are not specialized. 
This mean that if they use that resource to make more tablets, they will have less resource to produce smartphones. 

hope this helps