What Is Meant by Incomplete Dominance

What is meant by incomplete dominance?

A) The dominant allele in an X-linked trait is more likely to be expressed in males than in females.
B) The two alleles in a heterozygote each equally produce their own distinct phenotype.
C) In homozygotes only the dominant form of the allele is expressed.
D) Homozygotes have phenotypes in which the two forms of the allele are expressed separately.
E) Heterozygotes have a phenotype that is a mixture of the two alleles.