What is the most likely purpose of the gaucho games?

I believe the answer is: a. to honor the lost civilization of the guachos

In the past, Argentinean Gauchos was known as skilled horsemen that were feared by all of their enemies across the continent, which protect Argentinean territories from imminent danger.

Since the gauchos civilization no longer exist, The games was made to honor them.

The purpose of the gaucho games most likely is to show the skills of a gaucho while they fight with each other, ride a horse or trying to shoot a ring while riding a horse. A gaucho is horseman of the Argentine and Uruguayan grasslands.