How do a chromosome, a gene, and an allele differ?
How are they similar?

An allele or allelomorph [1] (from one to the other ») is each of the alternative forms that the same gene can have that differ in their sequence and that can be manifested in specific modifications of the function of that gene (They produce variations in inherited characteristics such as eye color or blood group). [2] Since most mammals are diploid, they have two sets of chromosomes, one of them from the father and the other of the mother. Each pair of alleles is located at the same locus or place on the chromosome.

C) reflection (i also looked up the other choices just to make sure)