If you're not in a rush(time limit) before your VA CHP expires or have another CHP to cover you I would just fill the blank with something obscure ... like "not since HS", or "not competitive".
I use to fill in all gov't forms as "Caucasian.
But after getting a recent DNA test I now use/have added "Asian" or "Native American". My DNA profile says so, to all the above plus a few more.
I've also wrote in "Mixed".
America is the melting pot and race can be how you self identify.
Example:
BOH, wrote "Afro-American" iirc even though his mother was white.
IMHO, whatever you write in is fine, as long as it isn't a "willfully" false statement.
INLNDIPOOTV, but I did lay
(I don't sleep) on a Sleep Number bed