Let d represent the difference in population mean for math scores and the population mean for writing scores. Which of the following best represents the null and alternative hypothesis you would use to test a difference between the population mean for the math scores and the population mean for the writing scores? A. H0 : d = 0, H a: d < 0 B. H0 : 1 - 2 > 0, H a: 1 - 2 = 0 C. H0 : d = 0, H a: d 0 D. H0 : d 0, H a: d 0 Select b. Calculate the test statistic. (Round your answer to two decimal places.) c. Calculate the p-value. (Round your answer to four decimal places.) d. At =0.05, what is your conclusion