During extended, intense exercise, a person begins to tire and breathe heavily. If this person continues to exercise, his muscles will soon switch from

a) aerobic respiration to anaerobic (alcoholic) respiration

b) anaerobic (lactic acid) respiration to aerobic respiration

c) anaerobic (alcoholic) respiration to aerobic respiration

d) aerobic respiration to anaerobic (lactic acid) respiration