How could you best predict the maximum number of alleles for a single gene whose polypeptide product is known?

A. Search the population for all phenotypic variants of this polypeptide.

B. Count the number of amino acids in the polypeptide.

C. Mate all known genotypes and collect all possible offspring different from the parents.

D. Count the number of DNA nucleotides that are in the code for the polypeptides.