Is telling a student to take an ethnicity test legal?

An admissions officer came to my school to talk with me about their medical school, one that I've already applied to. After they asked my grades, I was told I should take an ethnicity test to see if I was native american because "it may be worth it". After inquiring mostly about my first-generation background, age, if I planned on marrying and moving to a foreign country, and whether I had a fee waiver, I was told that I should withdraw my applications from all my medical schools. Throughout the hour-long encounter, I was constantly belittled and humiliated.