The share of industry output sold by the top four steel producers in the country are 19%, 15%, 12%, and 9% respectively. The four-firm concentration ratio for the steel industry is

The unemployment rates during the last 10 years in the Eurozone was

A) constantly lower than the unemployment rate in the United States and not rising toward the U.S. unemployment rate. B) constantly lower than the unemployment rate in the United States but were rising toward the U.S. unemployment rate. C) more or less constant at 3 percent. D) generally higher than the U.S. unemployment rate. E) approximately equal to those in the United States, with some years the U.S. unemployment rate being slightly higher and in other years the U.S. unemployment rate being slightly lower.

Refer to the graph below. It shows the total product (TP) curve. At which point does diminishing marginal returns set in?

A. Point a
B. Point b
C. Point c
D. Point d