On What Basis Does Forensic Biotechnology Distinguish One Individual from Another

On what basis does forensic biotechnology distinguish one individual from another?

A) Different people will have different mutations in their short tandem repeats.
B) Different people will have a different number of tandem repeats at the same location in their genomes.
C) Different people will have completely different genomes.
D) A small tandem repeat in one person will be in a different location in the genome of another person.