The national Institute of Health (NIH) set up a study to determine whether larger doses of vitamin C would shorten the length of time it take to recover from a cold. Three thousand volunteers were split into two groups. For two weeks, members of Group A took 3,000 mg of vitamin C daily. Group B received 3,000 mg of a placebo (contains no Vitamin C). At the end of the two-week period, the researchers inserted live cold viruses directly into the noses of all the volunteers. The volunteers in both Group A and B continued to take their daily pills. All the volunteers got colds, and there was no significant difference in length of time that they experienced cold symptoms. What may have been a possible hypothesis that this experiment addressed?