Drugs Like Aricept and Namenda That Are Currently Used to Treat

Drugs like Aricept and Namenda that are currently used to treat Alzheimer's disease tend to

A) have little measurable impact on behavioral or cognitive abilities.
B) positively impact cognitive functioning and reduce behavioral problems, but not slow the progression of the disease.
C) positively impact behavioral problems, but show little impact on cognitive functioning.
D) positively impact cognitive functioning, reduce behavioral problems, and slow the progression of the disease in some individuals.