Answer:
a. Czechoslovakia
Explanation:
<em>"On August 20, 1968, the Soviet Union led Warsaw Pact troops in an invasion of Czechoslovakia to crack down on reformist trends in Prague. Although the Soviet Union's action successfully halted the pace of reform in Czechoslovakia, it had unintended consequences for the unity of the communist bloc."</em>
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more detailed info found here; <em>https://history.state.gov/milestones/1961-1968/soviet-invasion-czechoslavkia</em>
The best option from the list would be that "<span>C. It ties the essay together and tell readers what they have learned and should remember," since the other options have to do with the beginning and middle of the essay. </span>
The answer is: Islam became the main religion