To preserve the original version of a workbook so you can make changes to a copy of it$,$ which of the following would you do$?$

a$)$ Leave the workbook closed.

b$)$ Open the workbook, change the first worksheet, and save it using the Save command.

C$)$ Open the workbook, make changes, and then save it using the same name.

d$)$ Open the workbook, make changes, and then save it using a different name.