An obligate anaerobe bacterium was grown in two test tubes filled with media rich in glucose. one tube was sealed to produce anaerobic conditions, and the other was not. an uninoculated, unsealed tube was used as a control. glucose utilization by this bacterium causes acid production, which is indicated by a lightening of the media color. if the bacterium is able to produce atp only by fermentation, which result do you expect to receive? a. lightening of media in the sealed tube only b. lightening of media in the unsealed tube only c. lightening of media in the sealed and unsealed tubes only d. lightening of media in the control tube only