A Nurse Is Explaining the Concept of Cognitive Aging to a Group

A nurse is explaining the concept of cognitive aging to a group of seniors at the senior center when one asks, "So when does this type of aging begin?" Which response by the nurse would be most appropriate?

A) "It usually starts sometime during your forties."
B) "Researchers have yet to identify exactly when it starts."
C) "It's a life-long process that starts before you were born."
D) "Each person begins this type of aging at different times."