During autumn months, passenger railroads across the globe deal with a condition called slippery rail. It results from a combination of water, leaf oil, and pressure from the train's weight, which creates a slippery black ooze that prevents trains from gaining traction. One solution for slippery rail is to cut back trees from all of a rail firm's rail network on a regular basis, thereby helping prevent the problem from developing. If incurred, would this railroad expense be a better example of a fixed cost or a variable cost? Why? A. This is an example of a fixed cost because the cost doesn't vary with the number of trains. B. This is an example of a variable cost because it is a long-run cost. C. The cost can be either fixed or variable depending on whether we are talking about the short run or long run.