**Core Concept**
Rivastigmine and Donepezil are centrally acting cholinesterase inhibitors that increase the concentration of acetylcholine in the brain by preventing its breakdown. This class of medications is primarily used in the management of Alzheimer's disease, a progressive neurodegenerative disorder characterized by cognitive decline and memory loss.

**Why the Correct Answer is Right**
These medications work by irreversibly inhibiting acetylcholinesterase, the enzyme responsible for breaking down acetylcholine in the synaptic cleft. By increasing the availability of acetylcholine, these drugs enhance cholinergic transmission in the brain, particularly in areas involved in memory and learning. This leads to a temporary improvement in cognitive function and symptoms in patients with Alzheimer's disease.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Rivastigmine and Donepezil are not primarily used in the management of Parkinson's disease, which is a neurodegenerative disorder characterized by motor symptoms such as tremors and rigidity. While both conditions involve degeneration of dopaminergic and cholinergic neurons, the pathophysiology and treatment approaches differ.
**Option B:** This option is incorrect because Rivastigmine and Donepezil are not primarily used in the management of hypertension, a condition characterized by high blood pressure. These medications do not have a direct effect on vascular tone or blood pressure regulation.
**Option C:** This option is incorrect because Rivastigmine and Donepezil are not primarily used in the management of epilepsy, a condition characterized by recurrent seizures. These medications do not have a direct effect on neuronal excitability or seizure threshold.

**Clinical Pearl / High-Yield Fact**
Rivastigmine and Donepezil can cause cholinergic side effects such as nausea, vomiting, and diarrhea due to the increased availability of acetylcholine in the peripheral nervous system. This is a reminder to carefully monitor patients for these adverse effects, especially in the early stages of treatment.

**Correct Answer: C. Alzheimer's disease.**