A large clinical trial was designed to determine whether a certain vitamin improves the general health of adults.The investigators first identified 85 variables that measure various aspects of the general health of adults. Because each adult in the clinical trial was to serve as his or her own control, the 85 variables were measured for each adult, both before taking the vitamin and after taking the vitamin for three months. The investigators then performed 85 matched-pair t-tests, one for each variable. They found statistically significant results at the 0.05evel in 2 of the variables, both in the direction of improved general health. Which of the following should the investigators conclude? 
选项为:A:There is evidence that the vitamin improves the health of adults because 2 of the 85 tests were statistically significant.  B:There is evidence that the vitamin improves the health of adults because in clinical trials investigators typically underestimate the proportion of the population that is helped by a vitamin.  C:There is insufficient evidence that the vitamin improves the health of adults because at the 0.05 significance level, one could easily get statistically significant results in 2 out of 85 tests just due to chance variability.  D:There is insufficient evidence that the vitamin improves the health of adults because the sample size of 85 is not large enough to draw a conclusion.  E:No conclusion can be drawn because an even number of variables is needed for a matched-pairs design.  请回答其中一个选项.