The Table Below Shows the Mean Number of Daily Errors $\quad$

The table below shows the mean number of daily errors by air traffic controller trainees during the first two weeks on the job. We want to perform a paired t-test at ? = .05 to see if the mean daily errors decreased significantly. $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\text { Trainee }$
$\begin{array}{|c|c|c|c|c|c|c|c|}\hline&\text { T1 } & \text { T2 } & \text { T3 } & \text { T4 } & \text { T5 } & \text { T6 } & T 7 \\\hline \text { Week 1 }&5.1 & 3 & 12.1 & 6.2 & 11.5 & 7.8 & 2.2 \\\hline \text { Week 2}&3.2 & 2.2 & 8.7 & 7.7 & 9.4 & 7.8 & 3.1 \\\hline\end{array}$ The test statistic is:

A) 1.25
B) 1.75
C) 0.87
D) 0.79