Why might a trade war develop?

A) After one nation enters into a mutually beneficial economic relationship with another, the second nation changes its government in a political war.

B) After one nation establishes trade barriers against another, the second nation retaliates with its own trade barriers.

C) After one nation begins to buy products from another, the second nation’s citizens begin a civil war to protest the exportation of those products.

D) After one nation attacks another, the second nation’s military invades the first.
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