The right answer is A. lactic acid fermentation to aerobic respiration.
Unlike aerobic exercise, anaerobic exercises involve intense physical effort and short, causing anaerobiosis in the muscles which forces them to switch to anaerobic respiration which is lactic fermentation (producing lactic acid and ATP (energy) from pyruvate), followed by a rest period, again providing oxygen to the muscles, allowing them to switch back to aerobic respiration.
An anaerobic exercise has the function of muscle, it does not burn fat. Nevertheless, by increasing muscle mass, it requires to spend more calories.