Even If Eugenics Laws Were Somehow Ethical, Why Would It

Even if eugenics laws were somehow ethical, why would it be difficult to apply them from a cultural standpoint?

A) Nobody is "normal."
B) Cultural definitions of "normal" or "attractive" change over time and from place to place.
C) Judges aren't smart enough to say whether someone is "abnormal."
D) Individuals' traits or personalities change over time.
E) It would be cheaper to "fix" abnormalities through medical psychological intervention.