What is likely phenotypic ratio resulting from a dihybrid cross with alleles showing epistatic interactions?

The answer is one (1) phenotype. This is because epistasis interaction of gene alleles involves the masking of one phenotype of an allele of a gene (at one or more loci) by the other.  Alternatively, the epistatic alleles may interact to cause a modification of a phenotype.

answer; atp and nadph;