Final answer:
Robert Hare, a psychologist, has focused his work on identifying the various traits of a psychopathic personality.
Step-by-step explanation:
A) Robert Hare is the correct answer. He is a renowned psychologist who has focused his work on identifying the various traits of a psychopathic personality. Hare is known for developing the Psychopathy Checklist, which is a widely used tool for assessing psychopathy.