The principle of dominance states that
a. all alleles are dominant.
b. all alleles are recessive.
c. some alleles are dominant and others are recessive.
d. alleles are neither dominant nor recessive.

some alleles are dominant and others are recessive

Explanation:

The principle of dominance states that some alleles are dominant and others are recessive. Alleles are alternative forms of a gene controlling a particular characteristic. Dominant allele are expressed phenotypically in the hybrid homozygous or heterozygous state. Recessive alleles are expressed phenotypically only in the homozygous condition.

an organism's phenotype is the  form of a trait  that it  displays. for  flowercolor, a pea  plant  can  display  a phenotype of purple or white flowers. an organism's  genotype  is the alleles of a gene it contains. based on his data, mendel concluded that a phenotype can be  determined  by more than one  genotype.