The academic literature about the effects of professional sports stadiums on the economy: Question 2 options: A) does not find any evidence of measurable economic effects of professional sports stadiums. B) finds that professional sports stadiums usually have significant positive effects on economic activity at the national level. C) finds that professional sports stadiums have mostly positive effects on local economic activity. D) finds that professional sports stadiums usually have a small, and possibly negative, effect on local economic activity