The breakup of the Austro-Hungarian Empire led to the creation of several new states and the expansion of others. These new states soon established trade restrictions and began collecting tariffs when goods crossed their borders. Which conclusion is most valid concerning the breakup of the Austro-Hungarian Empire?

A) International cooperation led to the settlement of border disputes.
B) Transition from a command to a free-market economy was difficult.
C) Political independence led to trade barriers.
D) Tariffs resulted in increased trade.