Final answer:
To tell Tableau that a field contains geographic information about states, you need to assign it a geographic role of 'State/Province'.
Step-by-step explanation:
To tell Tableau to recognize that a field contains geographic information about states, you need to assign the field a geographic role. In the case of a state field, you would assign it the geographic role of 'State/Province'.
To do this in Tableau, you can select the state field in the 'Data' pane, right-click on it, and choose 'Geographic Role' from the context menu. Then, select 'State/Province' from the list of available roles.
By assigning the state field the geographic role of 'State/Province', Tableau will understand that it represents geographic information about states and you can use it to create maps and perform spatial analysis.