Which of the following is an accurate comparison of Alzheimer and Parkinson diseases?

A) In both cases, the patient slowly loses memory and slowly drifts into inactivity.
B) In both cases, the patient becomes increasingly excited and overstimulated.
C) Patients with Alzheimer disease produce too much beta amyloid, while those with Parkinson produce too little dopamine.
D) Patients with Alzheimer disease produce too little beta amyloid, while those with Parkinson disease produce too little dopamine.
E) Patients with Alzheimer disease produce too much beta amyloid, while those with Parkinson disease produce too much dopamine.

Alzheimer disease and Parkinson disease are both neurodegenerative disorders that affect cognitive and motor functions, respectively. In Alzheimer disease, there is an abnormal accumulation of beta-amyloid protein in the brain, which leads to the formation of plaques and disrupts neuronal signaling. In contrast, Parkinson disease is characterized by the degeneration of dopamine-producing neurons in the brain, leading to a lack of dopamine, which is necessary for normal motor function. Therefore, patients with Alzheimer disease produce too much beta-amyloid, while those with Parkinson disease produce too little dopamine. Option C is the only accurate comparison that reflects this difference.