In its early stages, dementia is often _______________ from normal ageing, in which the older brain may naturally begin to show signs of cognitive impairment. Neither dementia nor cognitive ageing is currently _____________, though they may be slowed through diet, exercise, and keeping the mind agile with social and intellectual activity.

A

distinguishable; permanent

B

indistinguishable; reversible

C

differentiated; visible

D

irreversible; manageable