One of the scoring options you can configure when adding, or editing, a question is its "N/A"  scoring.

It is possible to mark any answer option, regardless of the answer text, as "N/A"  so that the selection of that option causes the question's points to be removed from scoring. You can mark more than one answer option as "N/A".

Enable "N/A" 

To mark an answer option as"N/A", simply check off the box in the column labelled "N/A" next to that answer option.

As expected, this results in the points for this question being ignored when the "N/A" option is selected:

Disable "N/A"

If we disable the "N/A"  setting for that answer option, the points will be scored for the "N/A" selection.

Now, when the N/A option is selected, points for it are scored.

Note that you do not have to turn off the "Omit N/A" setting on the Survey Settings page in order for this to work.