Coffee carts in Brisbane are a perfectly competitive industry in long-run equilibrium. One day, the Brisbane City Council imposes a $100 per month tax on each cart. How does this policy affect the number of cups of coffee consumed in the short run and the long run?

a down in the short run, no change in the long run b up in the short run, no change in the long run c no change in the short run, down in the long run d no change in the short run, up in the long run