Suppose all people with blonde hair have blue eyes and all people with dark hair have brown eyes. Which of the following would be the most likely explanation?

Suppose all people with blonde hair have blue eyes and all people with dark hair have brown eyes. Which of the following would be the most likely explanation?

a. Hair color is dominant over eye color.
b. There is no genetic variability in hair or eye color in the population.
c. Blue eyes are dominant over brown eyes.
d. Hair and eye color are on the same chromosome.