To organize the tables in the Data pane based on the type of data contained within the tables, you should use folders. Folders are a way to manually group fields, parameters, sets, or tables in the Data pane according to your preference. You can create folders by right-clicking on the fields or tables you want to group and selecting Folders > Create Folder. You can also drag and drop fields or tables into existing folders. You can name the folders according to the type of data they contain, such as sales, customer, product, etc. Folders can help you find and access the fields or tables you need more easily and efficiently. Reference:
Organize and Customize Fields in the Data Pane - Tableau
Tableau Certified Data Analyst Study Guide

When you sign in to a Tableau Server site from Tableau Desktop and search for a published data source, you will see all the data sources published to the site within the folders to which you have access. You will not see data sources published to other sites or folders that you do not have permission to view. You can also filter your search by project, owner, or tag. Reference: https://help.tableau.com/current/pro/desktop/en-us/connect_basic.htm https://help.tableau.com/current/pro/desktop/en-us/connect_tableauserver.htm

To use the Choose Region parameter to interact with a chart by toggling between different regions, you should add the [Region] = [Choose Region] formula to the Filters card. This formula will create a boolean filter that returns TRUE if the value in the Region field matches the value in the Choose Region parameter, and FALSE otherwise. You can add this formula to the Filters card by right-clicking on it and selecting Add Filter from the menu. Then you can select Condition from the dialog box and enter the formula in the text box. This will filter the chart to show only the data for the selected region.
The other options are not correct for this scenario. Adding Region to the Filters card will create a categorical filter that shows a list of values from the Region field, but it will not use the Choose Region parameter. Adding the Choose Region parameter to the Pages card will create a page control that allows you to cycle through different values of the parameter, but it will not filter the chart. Setting the Choose Region parameter to Single Value (list) will change how the parameter control appears on the worksheet, but it will not affect how it interacts with the chart. Reference: https://help.tableau.com/current/pro/desktop/en-us/parameters.htm https://help.tableau.com/current/pro/desktop/en-us/filtering.htm https://help.tableau.com/current/pro/desktop/en-us/filtering_condition.htm