Following the Civil War, U.S. currency included all of the following except:

Suppose that a country is producing on its PPC at a point to the left of the tangency between the trade line and the PPC. At the production point,

A) the opportunity cost in production of the good on the horizontal axis is less than its trade price. B) the opportunity cost in production of the good on the horizontal axis is more than its trade price. C) the opportunity cost in production of the good on the vertical axis is less than its trade price. D) the opportunity cost in production of the good on the horizontal axis may be either less than or more than its trade price.

Suppose prices for new homes have risen, yet sales of new homes have also risen. We can conclude that:

A. the demand for new homes has risen. B. the law of demand has been violated. C. new firms have entered the construction industry. D. construction firms must be facing higher costs.