Which of the following statements regarding Alzheimer disease is NOT correct?

A) Alzheimer disease is likely not a part of the normal process of aging.
B) Age alone is thought to be the underlying cause of Alzheimer disease.
C) The symptoms of Alzheimer disease are generally obvious at its onset.
D) Common signs of Alzheimer disease include paranoia and delusions.

Answer: B) Age alone is thought to be the underlying cause of Alzheimer disease.