What Would Be the Best Way to Distinguish Between Two

Multiple Choice

What would be the best way to distinguish between two alleles and two genes?

A) Examine the proteins they produce;most genes would produce very similar versions of the same protein,but two alleles would produce very different proteins.
B) Examine the proteins they produce;a gene produces one protein,and an allele produces two different proteins.
C) Examine their DNA;the DNA sequences of two different alleles would be more similar to each other than the sequences of two different genes.
D) You can't distinguish between them;there's no actual difference between alleles and genes.
E) Determine their chromosomal location;alleles will always be on different chromosomes,but genes will always be on different copies of the same chromosome.