You are estimating how much population A's proportion of answering yes to a question exceeds population B's proportion who say yes to the same question by using a confidence interval.

You have some ability to control the width of your interval.

Which of the following would be most likely to ensure that the confidence interval isnarrowed?

a.You increase both sample sizes and you decrease your confidence level.

b.You increase both sample sizes and you increase your confidence level.

c.You decrease both sample sizes and you increase your confidence level.

d.You decrease both sample sizes and you decrease your confidence level.