The traditional wisdom is that taking vitamin C supplements daily can effectively prevent a cold. However, a recent study found that this method has no obvious effect on most people. Which of the following, if true, would best support the above conclusion? ['People who exercise for a long time have fewer colds a year and heal faster than people who take vitamin C supplements.', 'In general, most people have an average cold 2 to 4 times a year, and those who take vitamin C supplements have a similar chance of having a cold.', 'Vitamin C supplements can reduce the duration of colds in adults by 8% and the duration of colds in children by 13.6%.', 'People who are often exposed to cold weather can reduce their chance of getting a cold by taking a vitamin C supplement daily.']