Final answer:
Some individuals may have only dominant traits, while others may have recessive traits depending on their homozygous or heterozygous status.
Step-by-step explanation:
When considering genetic traits, it's important to understand that not all individuals will have only dominant traits as this varies widely based on individual genotypes. Some individuals may exhibit only dominant traits, but others may have a combination of dominant and recessive traits, or only recessive traits depending on their genotype – whether they are homozygous or heterozygous for a given trait.
For a recessive trait to be observed in an individual, they must be homozygous recessive (answer c for the provided reference information) because having one dominant allele will mask the expression of a recessive allele. Hence, not all individuals will have only dominant traits, and conversely not all individuals will have more than one recessive trait, as this is dependent on each allele pair they possess.
As for the most common recessive trait, without specific information on Trait A, Trait B, and Trait C, it is impossible to answer definitively; therefore, the answer would be 'd) None of the above' unless there is data provided that identifies one of these as the most common in a particular population or context.
Lastly, with respect to the concept of multiple alleles, it’s important to note that while Mendel's initial studies suggested there were only two alleles for a given gene (one dominant and one recessive), we now understand that this is an oversimplification. In reality, multiple alleles may exist at the population level, and these can combine in various ways to produce different phenotypes. The most common phenotype or genotype is designated as the 'wild type,' and other variations are considered deviations from this norm.