A political campaign manager wants to test the effectiveness of a new 1 peen advertisement featuring Candidate X. The campaign manager takes a random sample of 300 voters before the ad goes on ek and another random sample of 250 voters afterwards, 158 of the 300 voters In the "before" sample say they support Candidate X and 140 voters In the "after" sample say they support Candidate X. If p, -the proportion of all voters who support Candidate X after the ad is alred and p,- the proportion of all voters who support Candidate X before the ad Is alred, which of the following is the correct standardized test statistic for He p,-py-0 0.56-0 527 0.56-0527 0.56(0.44) 0.527 (0473) 0.542 (0.458) 0.343(0.458) 250 300 250 300 To 100 0.56-0.527 0.56 -0327 0.542 (0.458) 056(040 0427(047)) 550 1250 1300 TWO 0.56-0.527 0.56 0.527 V 250 300