Variance of binomial:
Anp(1-p) = npq
Bnp
Cn²p²
Dp²
Answer & Solution
Correct answer: A. np(1-p) = npq
Var(X) = np(1-p) = npq. Maximum at p = 1/2. Each Bernoulli contributes p(1-p); n trials sum to np(1-p).
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