Both husband and wife have normal vision though their fathers were colour blind. The probability of their daughter becoming colour blind is:

Explanation

The correct option is 0% . For a daughter to be color blind, she must inherit one recessive color blindness allele from both her mother and father. Color blindness is a sex-linked recessive trait carried on the X chromosome. In this scenario, both parents have normal vision, indicating they do not carry the allele for color blindness. The probability of their daughter being color blind is 0% because neither parent carries the allele. Other options are incorrect because they suggest probabilities that do not align with the genetic transmission of a sex-linked recessive trait when neither parent is a carrier.