C The Aztec Empire was conquered by Hernán Cortés in 1519
By convincing others to support the industry duh
<span>D. Many of the natives quickly died from overwork and disease.</span>
The notional barrier separating the former Soviet bloc and the West prior to the decline of communism that followed the political events in eastern Europe in 1989.
"a. Immigration restrictions were expanded as fears of communist <span>infiltration from Soviet bloc nations spread" would be the best option from the list, since McCarthy instilled a feeling of paranoia about communism in the US.</span>
