Question

Asthma narrows airways to the lungs and in the lungs by contraction of muscles around the air passages, swelling of the airway lining, and build-up of excessive mucus. Because of this, asthma makes both the ___________ and ______________ systems work harder to deliver oxygen to the cells throughout the body.
A.respiratory; nervous
B.respiratory; muscular
C. respiratory; digestive
D. respiratory; circulatory