Your friend, a short-distance runner, needs to increase his ability to run long distances because he needs to fill in for a teammate who has surgery scheduled later in the year. Your friend has time to train to sustain a competitive pace for long-distance running, but he needs help planning exactly how to do that. Which of the following strategies would work? A Increase the total amount of time he runs for each workout. B Increase the distance he's used to running. C Increase the intensity at which he runs a few times each week. D Increase the number of days he runs each week.