5) Kendall owns a business vacuuming office building at night. His business currently services 85 offices per night. Kendall invests in higher-powered vacuums that allow him to service the same 85 offices in half the time. This is an example of: A) Productivity growth due to an improvement in physical capital per worker B) Decreased productivity due to an improvement in physical capital per worker C) An increase in the number of workers leading to an increase in GDP D) An increase in technical knowledge causing an increase in GDP but not an increase in productivity