**Core Concept**
Demyelinating disorders are characterized by the damage to the myelin sheath surrounding the axons of neurons in the central nervous system (CNS). This damage disrupts normal nerve conduction and leads to various clinical manifestations. The most common demyelinating disorders include multiple sclerosis (MS), acute disseminated encephalomyelitis (ADEM), and Guillain-Barré syndrome.

**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of demyelinating disorders. Demyelination is primarily caused by immune-mediated damage, where autoreactive T cells and antibodies target myelin proteins such as myelin basic protein (MBP) and proteolipid protein (PLP). This immune response leads to the activation of complement and the release of pro-inflammatory cytokines, which further exacerbate demyelination.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as demyelination can indeed occur in the context of infections, such as viral and bacterial infections, which trigger an immune response that targets myelin.
**Option B:** This option is incorrect as oligoclonal bands are indeed a characteristic feature of demyelinating disorders, particularly multiple sclerosis, and are often used as a diagnostic marker.
**Option C:** This option is incorrect as remyelination is a key feature of demyelinating disorders, where the damaged myelin sheath is repaired by oligodendrocyte precursor cells.

**Clinical Pearl / High-Yield Fact**
A classic exam trap is to confuse demyelinating disorders with axonal degeneration. Remember that demyelination is primarily an immune-mediated process, whereas axonal degeneration is often caused by direct axonal injury or toxic insults.

**Correct Answer: D. Remyelination is the primary process in demyelinating disorders.**