Answer:
The correct answer is option B, All four children have genes for blue eyes.
Step-by-step explanation:
The allele (representative of any trait) carried by genes expresses themselves at specific locus devise a phenotype. Traits exhibited can be represented by genotype and phenotype of an individual.
Here in this example, blue colour of eyes is a trait which is common in all the children of the family, this simply signifies that genes carrying the alleles is same in all the children.