In Constructing a Confidence Interval Estimate for the Difference Between

In constructing a confidence interval estimate for the difference between two population proportions, we:

A) pool the population proportions when the populations are normally distributed
B) pool the population proportions when the population means are equal
C) pool the population proportions when they are equal
D) never pool the population proportions to construct confidence interval for
E) always pool the population proportions to construct confidence interval for