If the nucleotide variability of a locus equals 0%,what is the gene variability and number of alleles at that locus?

A)gene variability = 0%; number of alleles = 0
B)gene variability = 0%; number of alleles = 1
C)gene variability = 0%; number of alleles = 2
D)gene variability > 0%; number of alleles = 2
E)Without more information, gene variability and number of alleles cannot be determined.