question: Q:A 53-year-old woman comes to the physician for a follow-up examination. One month ago, she was diagnosed with carcinoma of the left breast. She underwent a lumpectomy for a 2.1-cm mass and sentinel lymph node biopsy 2 weeks ago. The biopsy of the breast mass showed margin-free invasive ductal carcinoma; immunohistochemistry showed the carcinoma is estrogen-receptor and progesterone-receptor negative, and HER2-receptor positive. The lymph node biopsy was negative for metastases. Examination shows a healing surgical incision over the left breast. There is no palpable axillary lymphadenopathy. Her physician decides to initiate treatment with appropriate pharmacotherapy. Which of the following is the most appropriate next step in management?? 
  {'A': 'Echocardiography', 'B': 'Fundoscopy', 'C': 'Dual energy x-ray absorptiometry scan', 'D': 'X-ray of the chest', 'E': 'Endometrial biopsy'},