Co2 is the waste product of cellular respiration and fermentation. the yeast in this experiment are being grown in an oxygen poor environment and are thus performing alcohol fermentation. which of these statements correctly identifies the concentration in which yeast cells produce the most atp and why? a) 0% since no co2 was produced by the yeast cells. b) 10% since the co2 production is evidence of alcohol production. c) 50% since the co2 produced is evidence of atp production. d) 75% since it has the most glucose available for cellular respiration.