Rachel and Billy are conducting an experiment. The mass of their candle before burning was 7.0 grams. After burning the candle for six minutes, the mass went down to 5.5 grams. What can the students determine about the results of their experiment? A. The law of conservation of mass cannot be applied over short periods of time. B. The law of conservation of mass does not apply to chemical changes like burning. C. The law of conservation of mass was broken because the mass of the candle decreased. D. The law of conservation of mass was not broken because the missing mass was released as smoke