The correct answer is B. Allele.
An allele is one of two or more forms of a gene that arise by mutation and are found at the same place on a chromosome. Alleles determine an individual’s phenotype, or physical appearance. For example, the gene for eye color has two alleles, one for brown eyes and one for blue eyes. If an individual has two copies of the brown eye allele, they will have brown eyes. If they have one copy of each allele, they will have blue eyes.
A genome is the complete set of genetic information for an organism. It is made up of all the DNA in an organism’s cells. The human genome contains about 3 billion base pairs of DNA.
A genotype is the genetic makeup of an individual. It is determined by the alleles that an individual inherits from their parents. For example, an individual with the genotype BB has two copies of the brown eye allele.
None of the above is not the correct answer.