Brian Is a 70-Year-Old Man Who Has Recently Been Diagnosed

Brian is a 70-year-old man who has recently been diagnosed with Alzheimer's Disease. Because Alzheimer's Disease has a genetic component, Brian is worried that his family is also at risk of developing the neurological disorder. As the disorder progresses Brian has a difficult time remembering details about his personal life or even recognizing his own son.
-Which of the following is most likely implicated with the emergence of Brian's Alzheimer's Disease

A) Deterioration of his glial tissue
B) Deterioration of his neuronal dendrites
C) Deterioration of his neuronal axons
D) Deterioration of his neuronal synapses