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.

Since Sales is a measure, it can easily be depicted via size.
To drill down and change the level of detail, Country is the correct choice since it will contain STATE. We can then depict the various states by different shapes such as circle, square etc.
Finally, the Profit can be depicted via a color! Eg - Red for poor and green for excellent profits!

This is true, indeed!
The LEFT JOIN keyword returns all records from the left table (table1), and the matched records from the right table (table2). The result is NULL from the right side, if there is no match.

Explanation
View Data allows you to inspect your data in a spreadsheet-like layout. You can view data either for the data source as a whole, or to see the underlying data for an individual mark or a group of marks. In a worksheet, the rows that you see in the View Data window are always scoped to the current selection or the current view.
The View Data window displays as much of the data as possible by default, up to 10,000 rows. Field names are shown as column headers and can be dragged and dropped to change their display order. Click a column header to sort the values in that column.
From the official website:

The computer on which you are installing or upgrading Tableau Server must meet the minimum hardware requirements. If the Setup program determines that your computer does not meet the following requirements, you will not be able to install Tableau Server.
These minimum requirements are appropriate for a computer that you use for prototyping and testing of Tableau Server. They apply to single-node installations and to each computer in a distributed installation.