$\text { Happy Tots Child Care }$ Price of a Unit of Output

$\text { Happy Tots Child Care }$
$\text { Units of Labor per }~~\text { Output per Week }~~\text { Marginal Product }\\Week~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~per ~Week\\\begin{array}{|c|c|c|}\hline ~~~~~~~~~~~~~~~1~~~~~~~~~~~~~~~~~ & ~~~~~~~~4 ~~~~~~~~~& ~~~~~~~4~~~~~~~~ \\\hline 2 & 9 & 5 \\\hline 3 & 13 & 4 \\\hline 4 & 16 & 3 \\\hline 5 & 18 & 2 \\\hline\end{array}$
Price of a unit of output: $\$ 150$ per week.
Cost to Happy Tots of hiring one more unit of labor: $\$ 400$ per week.
Table 16.1 Refer to Table 16.1.What is the marginal revenue of the third unit of labor?

A) $300.
B) $450.
C) $600.
D) $1,200.