Which term refers to a legally established minimum price that firms may charge?

Refer to Table 1-2. What is Julius's marginal cost if he decides to stay open for three hours instead of two hours?

A) $0 B) $18 C) $54 D) $65

Which of the following would cause the present optimal extraction level of a nonrenewable resource to fall?

A. A reduction in extraction costs. B. A reduction in user costs. C. A reduction in total costs. D. A reduction in the price of the resource.