13) A farmer has decided to use a new additive to grow his crops. He divided his farm into 10 plots and kept records of the corn yield (in bushels) before and after using the additive. The results are shown below.
Plot:      1 2 3 4 5   6 7   8   9 10
Before   9 9 8 7 6   8 5   9 10 11
After    10 9 9 8 7 10 6 10 10 12
You wish to test the following hypothesis at the 1 percent level of significance.
H0: μD = 0 against H1: μD ≠ 0.
What decision rule would you use?
A) Reject H0 if test statistic is less than -3.250 or greater than 3.250.
B) Reject H0 if test statistic is greater than 3.250.
C) Reject H0 if test statistic is less than -3.250.
D) Reject H0 if test statistic is greater than -3.250 or less than 3.250.