Earth Movers & Shakers Operates 3 Iron Ore Mines Refer to the Table Above

Multiple Choice

Earth Movers & Shakers operates 3 iron ore mines.This table shows their daily production rates and the current number of miners at each mine.All of the miners work for the same wage and each miner in any given mine produces the same number of tons as each other miner in that mine. $$\begin{array} { | l | l | l | } \hline \text { Mine } & \text { Tons } & \begin{array} { l } \text { Number of } \\\text { Miners }\end{array} \\\hline \text { Mother Lode } & 100 & 25 \\\hline \text { Scraping Bottom } & 30 & 10 \\\hline \text { Middle Drift } & 75 & 15 \\\hline\end{array}$$
Refer to the table above.The opportunity cost of moving one miner from Middle Drift to Mother Lode is:

A) 1 ton.
B) 3 tons.
C) 4 tons.
D) 5 tons.