A student lifted weights after
 from school and felt his muscles
 they began to burn.  He couldn't continue
 lifting weights after doing
 exercise for a long time.  Is
 muscle fatigue is most likely
 due to:
 (1) the acceleration of the heartbeat and
 exhaustion of the heart
 (2) the accumulation of oxygen in the
 lungs
 (3) the lack of oxygen and the accumulation of
 waste in muscles
 (4) the lack of carbon dioxide in the
 muscles
 (1) the acceleration of the heartbeat and
 exhaustion of the heart
 (2) the accumulation of oxygen in the
 lungs
 (3) the lack of oxygen and the accumulation of
 waste in muscles
 (4) the lack of carbon dioxide in the
 muscles