<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 49-year-old woman presents with a mass in her left breast. She says she discovered the mass during a monthly self-examination 3 months ago and has been watching it since that time. She believes the mass has enlarged since she first discovered it. The patient denies any ulceration, weight loss, fatigue, night sweats, or nipple discharge. Her past medical history is significant for mild osteoporosis, managed with alendronate. The patient is afebrile, and her vital signs are within normal limits. On physical examination, there is a 4-mm-diameter left breast mass that is firm and non-tender on palpation. A mammogram of the left breast is performed but fails to display the mass. Which of the following is the best next step in the management of this patient?? A: Reassurance, B: Begin tamoxifen therapy, C: Repeat a mammogram in 6 months, D: Observe for 6 months and biopsy the mass if it persists, E: Perform an ultrasound of the left breast,  <response>: This is a patient with a palpable breast mass that is not seen on mammogram. The key findings are a 4mm firm, non-tender mass in a 49 year old woman that has been present for 3 months and appears to be enlarging. Mammogram did not detect the mass, which is not unusual for small masses under 5mm. The differential diagnosis includes both benign and malignant etiologies. The next step should be aimed at obtaining a tissue diagnosis to determine if the mass is benign or malignant.E: Perform an ultrasound of the left breast 