One student claims that yogurt is made by lactic acid fermentation. another claimer claims that yogurt is made by alcoholic fermentation. testing for which of the following substances could determine whether alcoholic fermentation or lactic acid fermentation was going on?
a) nad+
b) pyruvate
c) oxygen
d) carbon dioxide

D) Carbon dioxide

Explanation:

Yogurt is formed when a bacteria ferments the lactose in the milk into lactic acid, that is a direct transformation, when alcohol is produced the fermentation produces carbon dioxide and other elements, if the test results positive for carbon dioxide is because there is alcoholic fermentation, and if there is not the yogurt is being produced by lactic acid fermentation.