An evil thief has been stealing moped scooters from cowtown. the 'scooter bandit' has successfully stolen seventeen scooters from local citizens in a period of two months, leaving residents cowering in fear. one fateful night the thief takes detective willoughby's 'kaihatsu raging pink zebra 77cx', and while committing the crime, accidentally cuts himself. despite his escape, detective willoughby is able to recover blood evidence. however, it doesn't seem like it will be enough to use for identification. what should the detective do to get enough dna? a) western blot b) dna fingerprint c) gel electrophoresis d) polymerase chain reaction (pcr)