offset command selects automatically a chain, i don't want that

[KarolR]

i drew a line between two endpoints of other lines, and then used the offset command, trying to select only the new line, but all three were selected.
Even though i disabled constraint persistence, afterwards, and drew again the line, it still selects all three.
I think there are no constraints at all in the case of the disabled constraint persistence, i didn't see any, but, as i said, it still selects all three.

[Bishop]

Go ahead and offset all three line segments. After you complete the offset operation, you can either delete the two you don't want or set them to construction geometry.

[JD Mather]

i drew a line between two endpoints of other lines, and then used the offset command, trying to select only the new line, but all three were selected.
..

While in the Offset command - right click the mouse and you can turn off Loop Select, but beware that this is one of the few things (maybe the only thing) in Inventor that will remember the setting and it will be off next time you start Inventor, then you can't figure out why it won't offset a loop anymore.