Fruit Color in a Particular Plant Is Controlled by a Set

Multiple Choice

Fruit color in a particular plant is controlled by a set of three QTLs (quantitative trait loci,or "polygenes") that work in an equal and additive manner.Each QTL has two alleles (i.e. ,A and a) ;each allele represented by a capital letter produces one dose of yellow pigment,while alleles represented with lower case letters do not produce any pigment at all.
-A trihybrid plant (A/a;B/b;C/c) is selfed.Assuming no effects of the environment,what proportion of the offspring will have the same fruit color phenotype as the dihybrid parent?

A) 0.031
B) 0.125
C) 0.250
D) 0.312
E) 0.422