Imagine the U.S. were to move to eliminate most import tariffs for manufactured goods from all its major trading partners. In return, those trading partners eliminate most import tariffs for manufactured goods made in the USA. How would this likely affect the variety of products produced at individual manufacturing plants in the USA? Question 13 options: a) Plant-level product variety would decrease, especially for plants in industries whose products were subject to the highest import tariffs before the change in policy. b) Plant-level product variety would decrease, especially for plants in industries whose products were subject to the lowest import tariffs before the change in policy. c) Plant-level product variety would increase, especially for plants in industries whose products were subject to the highest import tariffs before the change in policy. d) Plant-level product variety would increase, especially for plants in industries whose products were subject to the lowest import tariffs before the change in policy