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

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