Which of the Following Best Describes the Etiology of Neurocognitive

Which of the following best describes the etiology of neurocognitive disorders?

A) The neural mechanisms that contribute to Alzheimer's disease are well known and understood.
B) The onset of vascular neurocognitive disorder is often abrupt and presents with a stepwise progression.
C) Frontotemporal lobar degeneration manifests with disturbances in motor skills.
D) Early symptoms of aphasia is what distinguishes Lewy body disease from Alzheimer's.