What Is the Role of Alleles in Polygenic Traits

What is the role of alleles in polygenic traits?

A) Dominant alleles are responsible for expressing the trait.
B) Recessive alleles play a major role in the final outcome of the trait.
C) For every two alleles, there is one polygenic trait.
D) Each allele has a small effect in determining the final phenotype.
E) Each allele has a massive effect in determining the final phenotype.