Which phrase best completes this diagram? 3 boxes showing Regional Economies in the United States. Text that reads: Regional Economies in the United States. Box 1 North. High industrialization. More factory workers. Box 2 West. ?. Box 3 South. More plantations. Rising slave labor. A. No plantations; Fewer slaves B. Less industrialization; More factory workers C. Some industrialization; Some slave labor D. More small farms; No slave labor