A 22-year-old woman, who works as a secretary for an accounting firm, has noted a palpable nodule on the side of her neck for the past 3 months. On physical examination, there is a 2-cm, firm, nontender nodule involving the right lobe of the thyroid gland. A fine-needle aspiration biopsy specimen of the nodule shows cells consistent with carcinoma of the thyroid. No other family members are affected by this disorder. Which of the following would be considered most relevant in the woman's past medical history? □ (A) Chronic alcoholism
□ (B) Ataxia telangiectasia
□ (C) Radiation therapy in childhood
□ (D) Blunt trauma from a fall
□ (E) Exposure to arsenic compounds