Table 6-A -Refer to Table 6-A

Table 6-A
$$\begin{array} { | c | c | } \hline \text { \# of Pickers } & \text { Total \# of Oranges Picked } \\\hline 1 & 1,000 \\\hline 2 & 2,000 \\\hline 3 & 3,000 \\\hline 4 & 3,900 \\\hline 5 & 4,700 \\\hline 6 & 5,400 \\\hline 7 & 6,000 \\\hline 8 & 6,200 \\\hline 9 & 6,000 \\\hline\end{array}$$
-Refer to Table 6-A.The marginal product of labor begins to diminish with the addition of the ____ picker.

A) fourth
B) fifth
C) seventh
D) eighth
E) ninth