A student is trying to design an experiment to determine the rate of alcohol fermentation of yeast in different concentrations of sugar solutions. One way to obtain quantitative data to graph the rate of fermentation in this experiment is to:

A. Measure the amount of CO2 gas produced over time.
B. Measure the amount of lactic acid produced over time.
C. Observe which sugar and yeast solution finishes the fermentation reaction first, second, third, etc.
D.Measure the amount of O2 gas produced over time.