To solve this problem, we need to understand the concept of DNA polymorphism and its applications.$\newline \bullet$DNA polymorphism refers to the variations in DNA sequences among individuals within a population. These variations can be in the form of single nucleotide polymorphisms (SNPs), insertions, deletions, or variable number tandem repeats (VNTRs).$\newline \bullet$Genetic mapping involves locating genes on a chromosome and determining the distance between them. DNA polymorphisms serve as markers that help in identifying the position of genes on chromosomes.$\newline \bullet$DNA fingerprinting is a technique used to identify individuals based on their unique DNA profiles. It relies on the detection of polymorphic regions in the DNA, such as VNTRs, to generate a distinctive pattern for each individual.$\newline \bullet$Both genetic mapping and DNA fingerprinting utilize DNA polymorphisms as a fundamental tool. Genetic mapping uses these variations to map genes, while DNA fingerprinting uses them to distinguish between individuals.$\newline$Therefore, DNA polymorphism forms the basis of both genetic mapping and DNA fingerprinting.$\newline$This corresponds to Option 3: Both genetic mapping and DNA fingerprinting.