Which Statement Best Describes the Catching of Serial Killers

Which statement best describes the catching of serial killers?

A) It is usually attributable to hard work and many hours on the part of the police.
B) It is often a matter of luck because serial killers often change their whereabouts and have little connection to their victims.
C) It is often a street person who turns the killer in.
D) It is often a school teacher who reports strangers lurking in schoolyards who turn out to be serial killers.