Which of the following was an economic spinoff of the success of automobiles? a. motelsb. coal industryc. railroadsd. clothing stores

A. motels

An economic spin-off refers to a potential secondary economic effect from the implementation of a new project. In this case, motels were an economic spin-off because they were an unintended effect of automobiles. As the popularity of the car rose, people started using it as a method of transportation for long-distance travel. This meant that road trips became more common, and the need to stop and rest gave rise to motels.

the constitution gives congress the power to regulate commerce "among" the several states.