O d. a statistical error QUESTION 22 A two-tailed hypothesis test is being used to evaluate a treatment effect with a = .05. If the sample data produce a z-score of z = -0.43, then what is the correct decision? a. Reject the null hypothesis and conclude that the treatment has no effect. O b. Fail to reject the null hypothesis and conclude that the treatment has no effect. O c. Reject the null hypothesis and conclude that the treatment has an effect. O'd. Fail to reject the null hypothesis and conclude that the treatment has an effect