John is creating a Thanksgiving display at the store where he works, using only canned pumpkin and canned green beans. He needs to maintain a ratio of pumpkin to green beans of 5 to 2. If he wants to use a total of 140 cans, how many cans of green beans should he use? A. 38 cans B. 40 cans C. 22 cans D. 7 cans