Task: Question Answering
Input (English): Background Paragraph: Animals and some bacteria and fungi carry out lactic acid fermentation. Lactic acid is a waste product of this process. Our muscles perform lactic acid fermentation during strenuous exercise, since oxygen cannot be delivered to the muscles quickly enough. The buildup of lactic acid is believed to make your muscles sore after exercise. Bacteria that produce lactic acid are used to make cheese and yogurt. The lactic acid causes the proteins in milk to thicken. Lactic acid also causes tooth decay, because bacteria use the sugars in your mouth for energy. 
Story: Ben and Jack both loved microorganisms. Jack decided to study more about lactic fermentation, while Ben decided to study more about protozoa. 
Question: Which person read more about lactic acid causing tooth decay?
Output (English): Jack.