December 14, 2024
Explanation:
(a) The completed sentence would be: "In its early stages, dementia is often indistinguishable from normal aging, in which the older brain may naturally begin to show signs of cognitive impairment. Neither dementia nor cognitive aging is currently reversible, though they may be slowed through diet, exercise, and keeping the mind agile with social and intellectual activity."
Explanation: "indistinguishable" is fitting as it suggests that dementia and normal aging may be difficult to tell apart, especially in their early stages. "reversible" is appropriate, indicating that neither dementia nor cognitive aging can currently be completely reversed.
The other options do not fit the context as well:
Option 1 includes "distinguishable" and "permanent," which may not accurately convey the idea that dementia and normal aging can be challenging to distinguish in their early stages.
Option 3 mentions "irreversible" and "manageable," which is not accurate because the sentence implies that dementia and cognitive aging may be slowed but not completely managed or reversed.
Option 4 introduces "differentiated" and "visible," which may not convey the intended meaning regarding the difficulty in distinguishing between dementia and normal aging.