Which process separates the fragments of DNA

Ans is 'a' i.e. Gel Centrifugation. "DNA sequencing is now an automated procedure. Although many protocols exist the most commonly used strategy is based on the Sanger method in which dideoxy- nucleotides are used to randomly terminate DNA polymerization at each of the four bases (A,G,T,C,). After separating the array of terminated DNA fragment using high resolution gel or capillary electrophoresis, it is possible to deduce the DNA sequence"Note - In many other sources, the question asked is slightly different: Which process separates the two helix of DNA.* DNA melting or separation achieved by subjecting the DNA to heat, guanidine or many other solvents.