The Following Table Shows the Total Number of Pizzas Produced

Multiple Choice

The following table shows the total number of pizzas produced by 7 workers.
Table 16-1 $$\begin{array} { | c | c | } \hline \begin{array} { c } \text { Number of } \\\text { workers }\end{array} & \begin{array} { c } \text { Total number of pizzas } \\\text { produced per day }\end{array} \\\hline 0 & 0 \\\hline 1 & 6 \\\hline 2 & 13 \\\hline 3 & 18 \\\hline 4 & 21 \\\hline 5 & 23 \\\hline 6 & 22 \\\hline 7 & 20 \\\hline\end{array}$$
-Refer to Table 16-1.If the pizza industry is competitive,the price of a pizza is $10,and the daily wage of a worker $30,then the pizza shop will hire _____ workers to maximize profits.

A) 2
B) 3
C) 4
D) 5