From 1980 to 1990, how much did the number of licensed motor carriers increase?

Answer: B — 40,000

The correct answer reflects the significant growth in the trucking industry during that decade. Between 1980 and 1990, the number of licensed motor carriers did indeed see an increase of approximately 40,000. This period marked a time of economic expansion and deregulation in the trucking sector, which contributed to more companies entering the market. Factors such as changes in regulations, increased demand for freight transport, and the rise of just-in-time delivery practices led many businesses to obtain licenses to operate as motor carriers. This increase in the number of licensed carriers not only illustrates the industry's growth but also highlights the competitive landscape that emerged during this era. Understanding the dynamics of this period is essential for grasping the evolution of the trucking industry and its regulatory environment, making this answer correct in the context of historical trends in commercial transportation.