Help finding where to change the Duplicate Offset.

I want to change the duplicate offset and the online help gives this as the way to do it:
"You can change the offset at which duplicates are created. Click Tools  Options and in the Document list of categories, click General, and type values in the Horizontal and Vertical boxes."
However, in the Options, I don't see "Document" in the list of categories.
Can anyone tell me how I can change the Duplicate offset?
Thanks!