What can the UPDATE command not do?

The UPDATE command in SQL is specifically designed for modifying existing rows within a table, making option A the correct choice in this context. The primary function of the UPDATE command is to change the values of one or more columns in rows that meet certain criteria, but it does not possess the capability to add new rows; this task is designated to the INSERT command.

When it comes to modifying existing rows (option B), the UPDATE command provides the necessary functionality to change data in specified columns. It allows for precise adjustments to data that already exists in the database.

Furthermore, the UPDATE command allows the user to indicate exactly which table’s rows should be modified (option C). This means that you can select a table in your database and apply your updates solely to that table’s records.

Additionally, the ability to use a WHERE clause to filter which rows to update (option D) makes the UPDATE command even more powerful. By using a WHERE clause, users can target specific records for update operations, ensuring that only the intended data is modified. Thus, option A is the only statement that accurately reflects a limitation of the UPDATE command.