How Can You Determine the Genotype of a Plant Showing

Multiple Choice

How can you determine the genotype of a plant showing the dominant phenotype of red color?

A) The phenotype reflects the genotype,so the plant must be homozygous for the trait.
B) Cross the red plant with a white plant to see if any white plants appear.
C) Cross the red plant with other red plants to see if any white plants appear.
D) Cross the red plant with a white plant to see if any red plants appear.
E) Cross the red plant with another red plant,and then cross the F₁ population with each other to see if any white plants appear.