The diagram shows a transverse section through the wall of a bronchus (not to scale). In a person who has chronic obstructive pulmonary disease (COPD), what occurs in each of the numbered structures?
- A1 contracts, 2 contracts, 3 inhibited, 4 not affected
- B1 contracts, 2 not affected, 3 overactive, 4 inhibited
- C1 relaxes, 2 contracts, 3 inhibited, 4 paralysed
- D1 relaxes, 2 not affected, 3 overactive, 4 overactive