When you click Salt Lake City in the view, the URL action will direct you to
https://en.wikipedia.org/wiki/Salt+Lake+City+Car+Dropoff+City. A URL action is a hyperlink that points to a web page or other web-based resource outside of Tableau. You can use URL actions to create an email or link to additional information about your data. To customize links based on your data, you can automatically enter field values as parameters in URLs3 In this case, the URL action uses https://en.wikipedia.org/wiki/<Car Dropoff City> as the URL target, where <Car Dropoff City> is a field value from the view. When you click Salt Lake City in the view, Tableau will replace <Car Dropoff City> with Salt Lake City in the URL target.
However, since spaces are not allowed in URLs, Tableau will encode them as + signs instead. Therefore, the final URL will be https://en.wikipedia.org/wiki/Salt+Lake+City+Car+Dropoff+City3 The other options are not correct because they do not reflect how Tableau encodes field values in URL actions.