A 49-year-old male presents to clinic with complaints of chest pain. He says the chest pain feels like a burning feeling and usually occurs after meals. He denies any other associated symptoms and denies radiation of his pain to his left arm or jaw. He rates his pain a 3/10. The patient has no past medical history. Further questioning reveals that the patient has tried over-the-counter medication which he states mildly improved his symptoms, although he does not remember the name of the medication. Physical examination reveals an obese male but is otherwise unremarkable. An EKG performed in the office shows normal sinus rhythm. Osteopathic structural examination and treatment of this patient’s condition should be focused on which of the following vertebral levels?