Martin always seemed to be looking for new clinics and physicians to get rid of a persistent back pain, the cause of which could not be ascertained despite several medical check-ups. Since physicians were unable to find the possible reason for his physical pain and he was not convinced with the medical test results, Martin was advised to consult a psychiatrist. In this instance, with which of the following is he most likely to be diagnosed?
A. Somatic symptom disorder
B. Dissociative amnesia
C. Generalized anxiety disorder
D. Hypochondriasis