If the value of the marginal product of physical capital is $30 and the price at which the good the physical capital is used to produce is sold at $15, the marginal product of the physical capital used is:

The primary source of revenue for the federal government of the United States are taxes tied to ________

A) property values B) rents and dividends C) export and import flows D) income

Which one of the following colonial groups actually benefited from the Navigation Acts?

a. Southern tobacco farmers b. New England shipbuilders c. colonists who bought goods imported from non-imperial sources d. No colonial group benefited from the Navigation Acts.