In the National AIDS Behavioral Surveys sample of 2673 adult heterosexuals, 0.2% (that's 0.002 as a proportion) had both received a blood transfusion and had a sexual partner from a group at high risk of AIDS. Explain why we can't use the large-sample confidence interval to estimate the proportion, p, in the population who share these two risk factors.
a. Large-sample confidence intervals should never be used when the sample proportion is smaller than 0.05.
b. There should be no problem using the large-sample confidence interval since the sample size was so large.
c. There should be no problem since the sample was random.
d. We can't assume that the sampling distribution of p^ is approximately Normal because n(p^) < 10.