Based on this information, what is Zuri's phenotype for the coat pattern trait?

 - a spotted coat
 - a black coat
Zuri's genotype for the coat pattern gene is aa. Zuri's genotype of aa has only a alleles. The a allele is for a black coat. So, Zuri's phenotype for the coat pattern trait must be a black coat.
To check this answer, consider whether Zuri's alleles are dominant or recessive. The allele for a black coat (a) is recessive to the allele for a spotted coat (A). This means A is a dominant allele, and a is a recessive allele.
Zuri's genotype of aa has only recessive alleles. An organism with only recessive alleles for a gene will have the recessive allele's version of the trait. So, Zuri's phenotype for the coat pattern trait must be a black coat.