The correct option is A Phenotype
The genotype refers to the genetic composition of an individual. AA represents two alleles that have been inherited from each of the parents. Hence, it is the genotype.
The genotype determines the traits that an organism displays, also termed as phenotype. Phenotype represents the observable characteristics of the organism. Hence, axial location of flowers represents the phenotype.
When both the alleles of the gene controlling a character are similar, then it is called homozygous condition. Example: AA, aa
When both the alleles of the gene controlling a character are dissimilar, then it is called heterozygous condition. Example: Aa.