Answer: The mother and the father are both heterozygous brown-eyed (Bb).
Explanation: Both parents are brown eyed because they both have a heterozygous allele (Bb) for brown eye. The heterozygous allele has one gene for brown eye (B) which is dominant over the recessive gene for blue eye (b). So when the two heterozygous brown eye individuals cross, there is a chance of having a blue eyed child (bb).
See the attached punnet square for more illustration.
