The post-colonial political climate of most latin american countries is best described

c. unstable; following independence, many countries experienced shifting political leadership, coups, and civil wars.

Explanation:

Most of the Latin American countries, after they gained independence, faced lots of troubles. The political leadership of the countries was changing very often, and that was due to multiple reasons, be it democratic elections, revolutions, overtaking, civil wars, dictatorship, bad politics, you really had it all. The region, not all, but solid portion of it, managed to consolidate, but it took a lot of time for that. There's still multiple countries in Latin America that are still having huge problems with terrible politics and incredibly high corruption.

sumerians were responsible.

2018 means 2018 ce or common era

there have been other eras too including bce, which included way more years.