You can choose the former to an extent, but the latter is biologically inherited.
So Obama isn’t African American, got it.
The point is, people inherit physical characteristics common to their enthnicity
Ethnicity is not genetic. Are you one of those yanks spewing nonsense such as “I’m 23% French that’s why I like mayonnaise”.
“race is imaginary”
That anyone said that is something you’re imagining. Also just because we’re imagining something doesn’t mean it’s not real. A judge is just a human in fancy clothes imagining to have power over you, try telling them that as a defendant they’ll be impressed at your reasoning skills. The bailiffs? Only imagining that they have to follow the judge’s orders.