Related to the Economics in Practice on Page 154: According

Related to the Economics in Practice on page 154: According to the Economics in Practice feature, productivity of the firms participating in the United States Technical Assistance and Productivity Program

A) grew only slightly in the first few years and then stopped growing in the years that followed.
B) doubled during the first two years and then declined for the rest of the decade.
C) grew by 15 percent in the first year and continued to grow for more than a decade afterward.
D) started off declining for the first decade but then grew during the second decade.