If a perfectly competitive firm shuts down in the short run, its total cost equals zero

Which of the following is considered per se illegal under the U.S. antitrust law?

a. An agreement to fix prices of commodities. b. An agreement to maintain certain technical standards. c. An agreement to operate only in specific regions. d. An agreement to follow identical production technique.

Table 7.2GDP for Newland?Nominal GDP(in billions of dollars)GDP deflatorCPI2001$5,900120.1128.320026,300123.0131.720036,800126.3136.5Based on Table 7.2, the real GDP for 2003 was

A. $8,588.4 billion. B. $4,981.7 billion. C. $5,384.0 billion. D. $9,282.0 billion.