Final answer:
Cuba was a significant threat to the United States during the Cold War due to its proximity and the Soviet Union's missile bases there, which could potentially target major American cities. This demonstrates the seriousness of the threat the United States faced during the Cuban Missile Crisis.
Step-by-step explanation:
During the Cold War, Cuba represented a significant threat to the United States due to its proximity and the strategic placement of Soviet missile bases on the northwestern coast. The Cuban Missile Crisis map you're mentioning illustrates the accessibility these missiles would have had to American cities had they been launched. Although the United States had a naval blockade around the island, it's the fact that the Soviet Union could target major American cities from such a near distance that was the principal concern. Option (d) 'Cuba's proximity to the United States made it possible for large-scale missile attacks' accurately depicts the situation. The extent of the Soviet missiles reach from Cuba, which included cities as far north as Chicago and as far west as Los Angeles, underscores the immediacy and scale of the possible threat.
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