The Chart Below Describes the Short Run Productivity of Workers

The chart below describes the short run productivity of workers at Paper Pushers Inc. ,an office support firm that has no variable costs other than labor. $$\begin{array} { | l | l | } \hline \text { Workers } & \text { Pages per Hour } \\\hline 1 & 40 \\\hline 2 & 75 \\\hline 3 & 105 \\\hline 4 & 125 \\\hline 5 & 140 \\\hline 6 & 150 \\\hline 7 & 155 \\\hline\end{array}$$
The VMP of the sixth worker is _____ than the VMP of the fourth worker because

A) less;the firm experiences economies of scale.
B) less;the sixth worker is less skilled than the fourth worker.
C) less;the firm experiences diminishing returns to inputs.
D) more;the workers can specialize and exploit comparative advantages.