Answer the question on the basis of the following supply information facing a single firm in a particular labor market: $$\begin{array}{l}\text{ Wage}Quantity\\ \begin{array}{ccc}\text{ Rate }& & \text{ Supplied }\\ \$5& & 1\\ 10& & 2\\ 15& & 3\\ 20& & 4\\ 25& & 5\end{array}\end{array}$$ Refer to the given information.The marginal resource (labor) cost of the third worker is:

A) $15.
B) $25.
C) $35.
D) $45.

The marginal resource (labor) cost is the cost of hiring one additional worker. In this case, the marginal cost of the third worker would be the difference in total cost between having two workers and having three workers.

Using the given information, we can see that the total cost of hiring two workers is $20 (2 workers x $10 wage rate). The total cost of hiring three workers is $45 (3 workers x $15 wage rate).

Therefore, the marginal resource (labor) cost of the third worker is $25 ($45 - $20). So, the answer is B) $25.