Stating that an organism is heterozygous is stating its a. phenotype. b. karyotype. c. genotype. d. test cross.

C, as genotype refers to the genetics, such as Aa, while phenotype refers to the physical part, such as short hair. 

This would be its genotype (C).

Phenotype is its outward appearance (so green pea plant)
Karyotype would be the array of chromosomes
Test cross would be if you mixed a green pea plant with a yellow pea plant (PP x pp)
Genotype would be the Pp (heterozygous - one of each allele - one dominant, one recessive)

Adaptatio