The most common tool of analysis in international finance for measuring the average value of a currency relative to several other currencies is

____________ is the change in total cost that results from a one unit increase in output

Fill in the blank(s) with the appropriate word(s).

Refer to the labor market diagrams. The case of bilateral monopoly is represented by Figure:

A.  5.
B.  4.
C.  2.
D.  1.