Answer
14. b.
Vital capacity (VC) decreases because lung elasticity decreases
Work Step by Step
As one gets older (after about 40 years of age), tissue changes in many body structures cause decreases in optimal functioning. For example, the diaphragm gets weaker and the elasticity of thoracic tissues and of the lung tissues decreases. The decline in lung tissue elasticity causes several respiratory volumes to decrease; these include the forced vital capacity (FVC), and the forced expiratory volume ( FEV).
