If Two Countries Had Completely Free Trade with Each Other,why

If two countries had completely free trade with each other,why might a multinational corporation still be created such that it holds factories in both countries?

A) The multinational corporation wants to gain access to markets to which it would not otherwise have access.
B) The multinational corporation does not trust that the drop in protectionist policies will be permanent.
C) Protections against input goods make the costs of production too high.
D) The multinational corporation wants access to cheaper labor in one of the countries.
E) The other country prevents the export of particular,key input goods.