Final answer:
During an asthma attack, bronchioles become constricted, and taking epinephrine causes them to dilate, improving breathing.
Step-by-step explanation:
During an asthma attack, bronchioles become severely constricted. This constriction happens due to inflammation and the contraction of muscles around the bronchioles. Epinephrine, when taken, causes these constricted bronchioles to dilate, which means they widen to allow better airflow to and from the lungs. Thus, the correct answer to this question is a) constricted; dilate.