Which of the following antihistamines is used for treating allergies?

Fexofenadine is an antihistamine that is commonly used to treat allergic symptoms such as sneezing, runny nose, and itchy or watery eyes. It works by blocking the action of histamine, a substance in the body that is responsible for allergic reactions. As a second-generation antihistamine, fexofenadine is preferred for its reduced sedative effects compared to first-generation antihistamines, making it suitable for individuals who need to manage allergies while maintaining their daily activities.

Other options might be used in the context of allergy treatment, but they serve different roles. Cromolyn is a medication that prevents the release of inflammatory mediators from mast cells, mainly used for asthma and not as a primary treatment for allergic symptoms. Montelukast acts as a leukotriene receptor antagonist and is mainly used for asthma management and allergic rhinitis but does not directly target histamine activity. Diphenhydramine, while effective as a first-generation antihistamine for treating allergies, is known for its sedative properties and is not recommended for everyday use due to its side effects. Fexofenadine stands out as the best choice for treating allergies because of its effectiveness and favorable side effect profile.