Many athletes inhale pure oxygen after exercise in an attempt to increase muscular reabsorption of oxygen. Measured continuously after exercise, however, the blood lactate levels of athletes who inhale pure oxygen are practically identical, on average, to those of athletes who breathe normal air. The lower the blood lactate level is, the higher the muscular reabsorption of oxygen is. If the statements above are all true, they most strongly support which of the following conclusions? ["The amount of oxygen reabsorbed by an athlete's muscles always remains constant.", 'The inhaling of pure oxygen has no legitimate role in athletics.', 'High blood lactate levels cannot be reduced.', "Athletes' muscular reabsorption of oxygen is not increased when they inhale pure oxygen instead of normal air."]