The answer is c. Some alleles are dominant, and some alleles are recessive.
Gregor Mendel established the principles of heredity. To explain his experiments and discoveries, he invented terms dominant and recessive in reference to traits.
The other statements are not true because the DNA and protein codes were researched and discovered almost a century after Mendel's work. The statement that offspring receive two copies of each allele from each parent cannot be true since offspring receive only one copy of each allele.
