Which Statement Is FALSE About Variations in Olfactory Ability

Which statement is FALSE about variations in olfactory ability?

A) People who develop Parkinson's or Alzheimer's disease become more sensitive to smells.
B) Individuals with olfactory impairment are more likely to die than those with intact smell.
C) Regular exercise can maintain or even improve the sense of smell of older adults.
D) Most anosmia and hyposmia are temporary and caused by the flu or sinus infections.