Problem: Carla is a personal trainer in a small boutique gym who is seeing a new client. Her client, Maxwell, is a triathlete and competes in professional races. Maxwell wants to improve his aerobic fitness, so Carla decides it is necessary to perform a cardiorespiratory assessment. However, Carla's facility does not have a metabolic cart to measure Maxwell's rate of oxygen utilization. Given these circumstances, which cardiorespiratory assessment is most appropriate to complete? Select one: a. YMCA 3-minute step test b. Rockport 1-mile walk test c. 1.5-mile run test d. VO2max test