Based on this information, what is this plant's phenotype for the flower position trait?

 - terminal flowers
 - axial flowers
The pea plant's genotype for the flower position gene is ff. The pea plant's genotype of ff has only f alleles. The f allele is for terminal flowers. So, the pea plant's phenotype for the flower position trait must be terminal flowers.
To check this answer, consider whether the pea plant's alleles are dominant or recessive. The allele for terminal flowers (f) is recessive to the allele for axial flowers (F). This means F is a dominant allele, and f is a recessive allele.
The pea plant's genotype of ff 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 flower position trait must be terminal flowers.