Which medication is a muscarinic agent that prevents bronchoconstriction caused by vagal discharge and is often used in both children and adults?
a. Ipratropium (Atrovent)
b. Salmeterol (Serevent)
c. Formoterol (Foradil)
d. Albuterol (Ventolin)
e. Theophylline (Theo-24)