<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:An otherwise healthy 13-year-old boy is brought to the physician because of asthma attacks that have been increasing in frequency and severity over the past 4 weeks. He was first diagnosed with asthma 6 months ago. Current medications include high-dose inhaled fluticasone and salmeterol daily, with additional albuterol as needed. He has required several courses of oral corticosteroids. A medication is added to his therapy regimen that results in downregulation of the high-affinity IgE receptor FcεRI on mast cells and basophils. Which of the following drugs was most likely added to the patients medication regimen?? A: Zileuton, B: Omalizumab, C: Theophylline, D: Infliximab, E: Nedocromiln,  <response>: This is a clinical vignette about a 13-year-old boy with poorly controlled asthma despite being on high-dose inhaled corticosteroids and long-acting beta-agonists. He has required multiple courses of oral corticosteroids. The question asks which medication would downregulate the high-affinity IgE receptor FcεRI on mast cells and basophils when added to his regimen. Choice A, zileuton, is a 5-LO inhibitor used as add-on therapy for asthma. It does not affect IgE receptors.Choice B, omalizumab, is an anti-IgE monoclonal antibody that binds to free IgE, downregulating FcεRI expression on mast cellsbasophils. This makes it the most likely choice.Choice C, theophylline, is a methylxanthine bronchodilator sometimes used as add-on therapy in asthma. It does not affect IgE receptors. Choice D, infliximab, is an anti-TNF alpha monoclonal antibody used for inflammatory conditions like rheumatoid arthritis. It does not affect IgE receptors.Choice E, nedocromil, is a mast cell stabilizer used as add-on therapy in asthma. It does not affect IgE receptor expression.B: Omalizumab 