<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 43-year-old woman comes to the physician for a routine examination prior to starting a new job as a nurse. Over the past year, the patient has had mild shortness of breath and a cough productive of white sputum, particularly in the morning. She immigrated to the United States from South Africa with her parents 40 years ago. She received all appropriate immunizations during childhood, including the oral polio and BCG vaccine. She has smoked two packs of cigarettes daily for 30 years and drinks one glass of wine occasionally. Her only medication is a multivitamin. Her temperature is 36.5C 97.7F, pulse is 74min, and blood pressure is 12460 mm Hg. Bilateral wheezing is heard throughout both lung fields. A complete blood count and serum concentrations of electrolytes, urea nitrogen, and creatinine are within the reference range. Which of the following is the most appropriate next step to evaluate for tuberculosis in this patient?? A: Tuberculin skin test, B: Sputum culture, C: X-ray of the chest, D: PCR of the sputum, E: Interferon-gamma release assay,  <response>: This question is asking about the most appropriate next step to evaluate for tuberculosis in a 43-year-old woman with symptoms of chronic cough, shortness of breath, and wheezing. She has risk factors of smoking and previous BCG vaccination. The choices given are different diagnostic tests for TB.A tuberculin skin test checks for a delayed hypersensitivity immune response to TB proteins. It can be falsely negative in active TB or immunosuppression. It can also be falsely positive due to previous BCG vaccination. A sputum culture is the gold standard for diagnosing active TB, by growing the bacteria. However, it takes weeks for results.A chest X-ray can show lung abnormalities suggestive of TB, but cannot definitively diagnose it. PCR of sputum detects TB DNA and gives rapid results, but has lower sensitivity than culture.An interferon-gamma release assay is a blood test of cell-mediated immune response to TB. It is not affected by BCG vaccination.E: Interferon-gamma release assay 