Suppose that of adults in District A support a new ballot measure, while of adults in District B support the same measure. Pollsters take an SRS of adults from District A and a separate SRS of adults from District B to see the difference between the sample proportions . What are the mean and standard deviation of the sampling distribution of ? Choose 1 answer: Choose 1 answer: (Choice A) A (Choice B) B (Choice C) C (Choice D) D