A coffee shop orders coffee and tea from a distributor who requires a minimum order of $720. A pound of coffee costs $8 and a pound of tea costs $12. To summarize the situation, the shop owner writes the inequality: 8c + 12t ≥ 720, where c is the number of pounds of coffee and t is the number of pounds of tea. Which graph's shaded region shows the possible combinations of coffee and tea the coffee shop can buy?