MegaCorp INC. is a large manufacturing firm that operates 5 factories in Dallas, 4 factories in Los Angeles, and 5 factories in Albany, New York. It operates a tightly connected order management system that coordinates orders, raw materials, and inventory across all 14 factories. The management wants to go for a cost-efficient data transmission solution for intermittent traffic (few megabits per Second) between the sites. What type of a WAN architecture and WAN service would you recommend? State and justify the rationale behind your choice.