In a study of 58 HIV positive mothers who gave birth to children, 11 children were HIV infected. The mean (standard deviation) CD4 count was significantly lower in mothers who were HIV transmissive [465 (271)] than in non-transmissive mothers [728 (274)]. Which of the following statements is correct?
A. A paired t-test was performed on these data as the two groups were dependent.
B. The null hypothesis states that the mean CD4 count in the population is the same among mothers who transmit and mothers who do not transmit HIV to their children.
C. The results are significant at the 5% level suggesting that the null hypothesis cannot be rejected.
D. CD4 counts in these women are likely to be normally distributed.
E. The 95% confidence interval for the mean difference in CD4 counts would contain zero.