Answer
The parents are both heterozygous. That is their genotypes ( both) must be A/a. Where "A" represents the dominant gene for normal pigmentation, and "a" represents the recessive gene for albinism.
Work Step by Step
Since the parents are normally pigmented then their genotype is either A/A or A/a. However, since the gene for albinism is recessive, then the albino child must be heterozygous recessive,that is has a genotype of a/a. This combination is only possible in the child if both parents are heterozygous for the pigmentation genes i.e. A/a.
