The countries which were involved against Paraguay in the Triple Alliance War were b. Argentina, Brazil, and Uruguay.
What was the Triple Alliance War?
This was a bloody war that is considered to be the most devastating war in Latin American history as Paraguay fought against the allied countries of Argentina, Brazil, and Uruguay.
Hence, we can see that this war was between 1864-and 1870 and involved the loss of over 90% of the Paraguayan male population in the conflict in the landlocked country.
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