Researchers had three groups of professional cyclists cycle for one hour at different levels of intensity. Members of groups A, B, and C cycled at rates that sustained, for an hour, pulses of about 60 percent, 70 percent, and 85 percent, respectively, of the recommended maximum pulse rate for recreational cyclists. Most members of Group A reported being less depressed and angry afterward. Most members of Group B did not report these benefits. Most members of Group C reported feeling worse in these respects than before the exercise. Which one of the following is most strongly supported by the information above? ['Moderate cycling tends to benefit professional cyclists physically as much or more than intense cycling.', 'Physical factors, including pulse rate, contribute as much to depression as do psychological factors.', 'For professional cyclists, the best exercise from the point of view of improving mood is cycling that pushes the pulse no higher than 60 percent of the maximum pulse rate.', 'The effect that a period of cycling has on the mood of professional cyclists tends to depend at least in part on how intense the cycling is.']