The correct option is C electrophoresis
DNA fragments generated by the restriction endonucleases in a chemical reaction can be separated by electrophoresis.
Centrifugation is used in the DNA extraction process.
The polymerase chain reaction is simply DNA replication in a test-tube.
Restriction mapping is a method used to map an unknown segment of DNA by breaking it into pieces and then identifying the locations of the breakpoints. This method relies on the use of proteins called restriction enzymes, which can cut, or digest, DNA molecules at short, specific sequences called restriction sites.