<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 6-year-old male is brought to the pediatrician by his mother because she is concerned about his breathing. She states that every once in a while he seems to have bouts of coughing but doesnt have any significant difficulty breathing. She demands that the pediatrician begin treatment with albuterol as she is convinced that her child has asthma. The pediatrician, not fully convinced, states that he will run a test that will help to rule out asthma as a diagnosis. To which of the following tests is the pediatrician referring?? A: Pulmonary function tests, B: Methacholine challenge test, C: CT scan, D: Chest ragiograph, E: Allergy testing,  <response>: This is a clinical vignette about a 6-year-old boy brought to the pediatrician by his mother due to concerns about his breathing. The key details are that he has intermittent bouts of coughing but no significant breathing difficulties. His mother is convinced he has asthma and wants albuterol treatment, but the pediatrician is not fully convinced and wants to run a test to rule out asthma. To identify the correct test, we need to consider which test would help confirm or rule out a diagnosis of asthma. Pulmonary function tests, methacholine challenge tests, and allergy testing can all be used to evaluate lungairway function and hyperreactivity characteristic of asthma. A CT scan and chest x-ray would not directly evaluate lung function. Of the options, the methacholine challenge test is the most definitive for diagnosing asthma by evaluating airway hyperreactivity.B: Methacholine challenge test 