(Table) Based on the Table, the Value for a Is

(Table) Based on the table, the value for A is
$\begin{array}{c}\text { Competitive Labor Market }\\\begin{array}{|c|c|c|c|c|c|}\hline L & Q & M P P & \boldsymbol{P} & \boldsymbol{M M P} & \boldsymbol{W} \\\hline 0 & 0 & 0 & 8 & 0 & 80 \\\hline 1 & 5 & 5 & 8 & 40 & 80 \\\hline 2 & 11 & 6 & 8 & 48 & 80 \\\hline 3 & 18 & 7 & 8 & 56 & 80 \\\hline 4 & \mathrm{~A} & 9 & 8 & 72 & 80 \\\hline 5 & 38 & \mathrm{~B} & 8 & 88 & 80 \\\hline 6 & 50 & 12 & 8 & \mathrm{C} & 80 \\\hline 7 & 61 & 11 & 8 & 88 & 80 \\\hline 8 & 71 & 10 & 8 & 80 & 80 \\\hline 9 & 80 & 9 & 8 & 72 & 80 \\\hline 10 & 85 & 5 & 8 & 40 & 80 \\\hline\end{array}\end{array}$

A) 27.
B) 25.
C) 29.
D) 31.