In a Study of the Effectiveness of Physical Exercise in Weight

In a study of the effectiveness of physical exercise in weight reduction, 12 subjects followed a program of physical exercise for two months. Their weights (in pounds) before and after this
Program are shown in the table. Use Wilcoxon's signed -ranks test and a significance level of
0.05 to test the claim that the exercise program has no effect on weight. $\begin{array} { l l l l l l l l l l l l l } \text { Before } & 162 & 190 & 188 & 152 & 148 & 127 & 195 & 164 & 175 & 156 & 180 & 136 \\\hline \text { After } & 157 & 194 & 179 & 149 & 135 & 130 & 183 & 168 & 168 & 148 & 170 & 138 \\\hline\end{array}$

What would be the signed rank for the column with values of 175 and 168 ?

A) 8
B) 9
C) 10
D) $8.5$