Points on a production possibilities curve are ________ and ________

Which of the following statements is correct? I. When economists derive the aggregate demand curve, they are looking at the effect of the price level on one commodity only. II. Any non-price-level change that increases aggregate spending on domestic goods shifts the AD curve to the right.

A) I only B) II only C) Both I and II D) Neither I nor II

Do all valuable items have price tags?

A. No, because some valuable items have no opportunity cost. B. Yes, because everything has its price. C. Yes, because price is the measure of opportunity cost. D. No, some have no explicit price on them. E. Yes, because only items that can be sold in markets have value.