You are answering a USMLE-style medical question. Question: A 59-year-old woman comes to the physician 2 weeks after noticing a lump in her left breast. Examination of the left breast shows a firm, nontender mass close to the nipple. Mammography shows an irregular calcified mass. A core needle biopsy shows invasive ductal carcinoma. Genetic analysis of this patient's cancer cells is most likely to show overexpression of which of the following genes? Options: A) HER2 B) BCR-ABL C) BRCA-2 D) BCL-2 Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.