Which of the following is an example of a sex-linked trait?

Color blindness is an example of a sex-linked trait because it is primarily carried on the X chromosome. In humans, males have one X and one Y chromosome (XY), while females have two X chromosomes (XX). Since color blindness is recessive, males are more likely to express the trait if they inherit the allele for color blindness on their single X chromosome. Females, on the other hand, would need to inherit the recessive allele on both of their X chromosomes to exhibit color blindness. This pattern of inheritance is characteristic of sex-linked traits, demonstrating how the location of a gene on a sex chromosome affects its expression and prevalence in individuals of different sexes.

The other traits listed do not follow this sex-linked inheritance pattern; height is influenced by multiple genes and environmental factors, eye color is also controlled by many genes not located on sex chromosomes, and blood type is determined by specific alleles of a gene that is not located on the sex chromosomes either.