We can use the normal distribution to make confidence interval estimates for the population proportion, p, when​

A) ​np > 5.
B) ​n(1 - p) > 5.
C) ​p has a normal distribution.
D) ​both np > 5 and n(1 - p) > 5.

Both conditions np > 5 and n(1 - p) > 5 must be satisfied to ensure that the normal distribution can be used for confidence interval estimates for the population proportion, p. This ensures that the sample size is large enough and the sample proportion is not too extreme.