Inheritance: determine question

In a plant species, flower colour is controlled by two unlinked genes, A and B. Gene A controls pigment production: the dominant allele A allows pigment production, while the recessive allele a prevents pigment production, resulting in white flowers. Gene B controls the type of pigment: the dominant allele B produces red pigment, and the recessive allele b produces blue pigment. However, if the plant has no pigment (aa), the flowers are white regardless of the B genotype. A cross between two plants with red flowers produced offspring with the following phenotypes:

Determine the genotypes of the two parent plants and explain how epistasis influences the phenotypes of the offspring.