This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Asthma, Subject name: Pharmacology
In a case of acute exacerbation of asthma, salbutamol was given and no improvement noticed, intravenous corticosteroids and aminophylline was given and condition improved. What is the mechanism of corticosteroid in acute asthma? 
Select and explain. 
A. Corticosteroid increase bronchial responsiveness to salbutamol, B. Corticosteroids cause direct bronchodilation when used with xanthines, C. Corticosteroids indirectly increase the effect of xanthines on adenosine receptor, D. Corticosteroids increase mucociliary clearance.
A: Corticosteroid increase bronchial responsiveness to salbutamol
Answer: A: Corticosteroid increase bronchial responsiveness to salbutamol 
Explanation: ANS. ACorticosteroids has a dual effect in acute asthma with an early facilitatory effect on airway beta 2 adrenoreceptor sensitivity and a later effect on airway inflammation, which further emphasizes the need for corticosteroids to be administered as early as possible during an acute asthma attack.# Newer monoclonal antibodies in respiratory condition1. Pitakinra: IL-3 and 4 antagonist (used in bronchial asthma)2. Resilizumab: IL-5 antagonist (used in bronchial asthma)3. Mepolizumab: IL-5 blocker (useful in hypereisnophilic vasculitis)4. Omalizumab: Against IG E (in bronchial asthma)5. Pavilizumab: Used against respiratory syncitial virus (AIIMS November 2016).