To solve this question, the user needs to know how the SQL SELECT statement and concatenation operator (||) work. The SELECT statement retrieves data from a database table and returns a result set. The concatenation operator is used to combine two or more strings into a single string.
The given SQL query concatenates three columns (address1, address2, and address2) using the concatenation operator and then renames the concatenated column as "Address".
The resulting query output will contain only one column named 'Address' that is the result of concatenating the three columns. Therefore, the correct answer is: