Table 2-4 -Refer to Table 2-4

Table 2-4
$$\begin{array} { | l | l | } \hline \text { Mobile Phones } & \text { Pizzas } \\\hline 0 & 10,000 \\\hline 200 & 8,000 \\\hline 500 & 6,000 \\\hline 900 & 4,000 \\\hline 1400 & 2,000 \\\hline 2000 & 0 \\\hline\end{array}$$
-Refer to Table 2-4. Consider the production possibilities table for an economy that produces only mobile phones and pizzas. What is the opportunity cost of increasing production of pizzas from 4,000 to 6,000?