Which of the following is a short-acting beta2 agonist?

Albuterol is recognized as a short-acting beta2 agonist and is commonly utilized in the management of asthma and other respiratory conditions. It works by binding to beta2-adrenergic receptors in the bronchial smooth muscle, leading to relaxation and dilation of the airways, which facilitates easier breathing. This rapid onset of action (typically within minutes) makes albuterol an effective rescue medication for acute asthma symptoms or bronchospasms.

The other options listed do not function as short-acting beta2 agonists. Omalizumab is an immunomodulator that is used for chronic asthma management and works by inhibiting the immunoglobulin E (IgE) response. Cromolyn sodium is a mast cell stabilizer that prevents the release of inflammatory mediators but does not provide immediate bronchodilation like beta2 agonists. Montelukast is a leukotriene receptor antagonist that helps to reduce inflammation and bronchoconstriction over a longer period but does not act as a short-acting bronchodilator. Therefore, the distinctive mechanism of action and therapeutic application of albuterol clearly classify it as a short-acting beta2 agonist.