Diagnosis of Somatic Symptom Disorder

In the context of Somatic Symptom and Related Disorders, a 32-year-old woman visits a psychologist complaining of persistent abdominal pain that has not responded to any medical treatment. Despite extensive medical evaluations that reveal no physiological basis for her symptoms, she continues to express significant distress over her physical symptoms, often seeking reassurance and multiple medical opinions. Given her situation, which of the following diagnoses would most accurately fit her condition?