The correct answer is D) Both Vietnam and Korea were divided into a communist north and non-communist south.
The way in that the political situation in Vietnam resembled that of Korea in the 1950s was that Both Vietnam and Korea were divided into a communist north and non-communist south.
In the Vietnam War, the Soviet Union supported the armed forces of the North, meanwhile, the United States supported South Vietnam. The USSR wanted to spread Communist all over Vietnam and the United States wanted to stop Communist and that is why it sent troops and support to South Vietnam. Something similar happened in the Korea War. The Soviet Union supported North Korea and the spread of Communism. The US did not want Communism to spread into South Korea and the US, Great Britain, and other allies supported South Korea. Both conflicts increased the tensions between the US and Russia during the Cold War years.