Select the false statement.

A. One should use z-numbers when estimating the population proportion.

B. When one knows the standard deviation of thepopulation, one must use t-numbers to determine the width of a confidence interval.

C. When t-numbers are used for computing the width of aconfidence interval, the corresponding Student's t-distribution follows (n-1) degrees of freedom, where n is the sample size.

D. If all other relevant variables are kept the same,thanthe bigger the sample size,the narrower the confidence interval is.