Arianna Is Perfectly Fluent in English and French

Multiple Choice

Arianna is perfectly fluent in English and French. Research has shown that such balanced proficiency in two languages

A) can accelerate the onset of Alzheimer's disease by four or five years.
B) decreases control over attention and lowers the ability to switch attention to new stimuli when needed.
C) helps build up a cognitive reserve that can protect against cognitive decline in late adulthood.
D) may result in delayed language development, learning problems, and lower intelligence.