Final answer:
The JOIN...USING keywords in SQL are not specifically for tables without common columns; they focus on matching columns with the same names across tables to determine the rows to combine in query results.
Step-by-step explanation:
The JOIN...USING keywords in SQL are utilized when you are working with two tables that have at least one column with the same name and compatible data types, but not necessarily for tables lacking a commonly named and defined column. This type of join focuses on matching columns that have the same names in both tables to determine which rows to combine in the query results. Therefore, the correct answer to the question is C) Matching columns.
When considering whether one of the tables is more correct than the other, the answer depends on the specific schema and purpose of the database. The correctness of a table is determined by its ability to efficiently and accurately represent the required data. Grouping the data differently can provide various advantages, such as optimizing query performance or simplifying data relationships. The decision to switch between tables or group data in a particular way should be guided by these considerations.