Which of the following medications are classified as ultrashort-acting adrenergic bronchodilators based on their duration of action?

1. Racemic epinephrine
2. Formoterol
3. Albuterol
4. Indacaterol
5. Arformoterol
6. Olodaterol

a. 1, 2, and 4 only
b. 1 only
c. 4 and 7 only
d. 1, 4, 7, and 8 only

ANS: B