Individuals with Asthma Have Difficulty Exhaling

Individuals with asthma have difficulty exhaling.Air has to pass through the same narrowed airway on the way in and out,why would exhaling be more difficult than inhaling?

A) Air is denser when it is exhaled.
B) People have to concentrate on exhaling,while inhaling is a reflex.
C) Exhaling requires more energy than inhaling.
D) Inhaling normally uses diaphragm contractions,while exhaling is normally passive except during an asthma attack exhaling requires additional muscles.
E) The alveoli have lost their walls,and cannot push the air out anymorE.