In a Wild-Type Fungus,protein E (Encoded by the Haplosufficient Gene

In a wild-type fungus,protein E (encoded by the haplosufficient gene "E") normally homodimerizes,and the E-E dimer catalyzes a biochemical reaction necessary for the production of a dark pigment.E^D represents a mutant,dominant,negative allele of gene E.What is the predicted phenotype of a fungus cell of genotype E⁺/E^D,and why?

A) mutant (no pigment production) ,as E is haplosufficient
B) mutant (no pigment production) ,as no E-E dimers will form in the heterozygous
C) mutant (no pigment production) ,as the mutant allele E^D is dominant
D) wild type (normal production of the dark pigment) ,as E^D is a negative allele
E) wild type (normal production of the dark pigment) ,as E is haplosufficient