Which of the following statements is correct? a. A table can contain a maximum of only one column marked as unused. b. You can delete a table by removing all columns in the table. c. Using the SET...

Which of the following statements is correct?

a. A table can contain a maximum of only one column marked as unused.

b. You can delete a table by removing all columns in the table.

c. Using the SET UNUSED clause allows you to free up storage space used by a column.

d. None of the above statements are correct.