Answer: 1).in the north west slavery wasnt allowed there
Explanation:
I would go for:
<span>North had a more widespread network of railroads available for delivering troops and supplies to the battlefield.</span>
Internment of Japanese Americans. The internment of Japanese Americans in the United States during World War II was the forced relocation and incarceration in concentration camps in the western interior of the country of about 120,000 people of Japanese ancestry, most of whom lived on the Pacific Coast.
If the border with Laos had been closed and North Vietnam had not been able to operate in the country, the communist side would not have been able to stock up on resources, men, ammunition, weapons, food and medicine through the HoChi Minh Trail.
Therefore, the forces of the North that were fighting in South Vietnam would have been out of supply, and their defeat would have been imminent.