Based on this information, what is this plant's phenotype for the pod color trait?

 - green pods
 - yellow pods
The pea plant's genotype for the pod color gene is dd. The pea plant's genotype of dd has only d alleles. The d allele is for yellow pods. So, the pea plant's phenotype for the pod color trait must be yellow pods.
To check this answer, consider whether the pea plant's alleles are dominant or recessive. The allele for green pods (D) is dominant over the allele for yellow pods (d). This means D is a dominant allele, and d is a recessive allele.
The pea plant's genotype of dd has only recessive alleles. An organism with only recessive alleles for a gene will have the recessive allele's version of the trait. So, the pea plant's phenotype for the pod color trait must be yellow pods.