During the sixty years since 1960, the sources of labor productivity growth include A. the global financial turmoil of 2008-2009 that made labor more productive B. the focus on saving energy during the 1970s C. the wide-spread introduction of the Internet during the 1970s D. plastics, the laser, and the computer during the 1960s, and the Internet during later years Comparing the 1960s to the more recent decades, labor productivity growth _ A. due to physical capital and human capital growth was greater in the 1960s B. due to technological change was smaller in the 1960s C. in the 1960s was smaller D. in the 1960s was approximately 25 percent higher