Genomic Regions with a Variable Number of Tandem Repeats (VNTRs)

Genomic regions with a variable number of tandem repeats (VNTRs) used in DNA typing are highly polymorphic with many different possible genotypes existing in a population. However, matching patterns of bands for any one VNTR between the DNA in a sample and the genomic DNA of a particular individual is not sufficient to establish that the two come from the same individual. The primary reason is that:

A) the DNA sample could be contaminated.
B) the gel may have been handled improperly.
C) the individual in question may have a twin.
D) any one VNTR could match in two individuals by chance.
E) VNTRs have multiple alleles and many possible genotypes.