To use a normal approximation to the binomial, which of the following must be true?

A. np 10, n(1 - p) 10 (some textbooks say np 5, n(1 - p) 5).

B. Each trial must be independent.

C. If you're sampling, the population size must be at least 20 times as large as the sample size (some textbooks say ten times as large).

D. None of the above

E. All of the above