Some researchers claim that herbal supplements such as ginseng or ginkgo biloba enhance human memory, To test this claim, a rescarcher selects a sample of n - 49 college students. Each student is given a ginkgo biloba supplement daily for six weeks and then all the participants are given a standardized memory test. For the population, scores on the test are normally distributed with 4 - 80 and o=21. The sample of n - 49 students had a mean score of M-85. Did the herbal supplements increase memory (a = .01)? a) Fail to reject the null hypothesis, p<.01. the herb significantly increased scores on memory test. ob reject null hypothesis p memory. c>01. The herb did not have a significant effect on memory Od) Fail to reject the null hypothesis,p>.01. The herb did not significantly increase memory