Which statement correctly explains the function of elastic fibres in the lungs?
- AThey allow the walls of stretched alveoli to recoil as air is breathed out.
- BThey increase in the walls of alveoli as a result of the release of the enzyme elastase.
- CThey increase in the walls of the alveoli as emphysema develops.
- DThey prevent the walls of the alveoli from collapsing as air is breathed in.