<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 28-year-old man comes to the physician because of a 1-year history of chronic back pain. He explains that the pain started after getting a job at a logistics company. He does not recall any trauma and does not have morning stiffness or neurological symptoms. He has been seen by two other physicians for his back pain who did not establish a diagnosis. The patient also has abdominal bloating and a feeling of constipation that started 3 weeks ago. After doing extensive research on the internet, he is concerned that the symptoms might be caused by pancreatic cancer. He would like to undergo a CT scan of his abdomen for reassurance. He has a history of episodic chest pain, for which he underwent medical evaluation with another healthcare provider. Tests showed no pathological results. He does not smoke or drink alcohol. He reports that he is under significant pressure from his superiors due to frequent performance evaluations. He takes daily multivitamins and glucosamine to prevent arthritis. His vital signs are within normal limits. Examination shows a soft, non-tender, non-distended abdomen and mild bilateral paraspinal muscle tenderness. The remainder of the examination, including a neurologic examination, shows no abnormalities. Laboratory studies are within the reference range. An x-ray of the spine shows no abnormalities. Which of the following is the most likely explanation for this patients symptoms?? A: Malignant neoplasm, B: Atypical depression, C: Irritable bowel syndrome, D: Somatic symptom disorder, E: Acute stress disorder,  <response>: This is a clinical case scenario involving a 28-year-old man with a 1-year history of chronic back pain that started after beginning a new physically demanding job, as well as recent abdominal symptoms. He has undergone previous medical evaluation that has not revealed any abnormalities. On exam, he has mild paraspinal tenderness but is otherwise normal, including a normal abdominal exam and normal labsimaging. The abrupt onset of back pain after beginning a new physically demanding job points towards a musculoskeletal cause. The normal workup makes serious pathology like cancer very unlikely. The abdominal symptoms are nonspecific but could be consistent with irritable bowel syndrome. Most importantly, his excessive health anxiety and concern about pancreatic cancer despite repeated normal evaluation and lack of risk factors points strongly towards somatic symptom disorder as the most likely diagnosis.D: Somatic symptom disorder 