A 12-year-old with moderate persistent asthma has had two exacerbations in the past year despite low-dose inhaled corticosteroid (ICS) with as-needed SABA. Which regimen is the preferred step-up according to current US guidance?AIncrease to high-dose ICS plus SABA PRNBAdd a leukotriene receptor antagonist to current ICSCUse low-dose ICS-formoterol as both maintenance and reliever (SMART)DStart daily oral theophylline with SABA PRNEAdd tiotropium and continue SABA PRNCheck my answer