**Core Concept**
The "Eye of the Tiger" sign on MRI refers to a specific imaging finding characterized by a central area of low signal intensity on T2-weighted images surrounded by a ring of high signal intensity, resembling the "eye" of a tiger. This radiological feature is associated with certain neurodegenerative disorders.

**Why the Correct Answer is Right**
The Eye of the Tiger sign is observed in conditions where there is a combination of iron deposition and gliosis in the substantia nigra. In Hallervorden-Spatz syndrome (now known as Pantothenate kinase-associated neurodegeneration, PKAN), the sign is due to the accumulation of iron in the globus pallidus and substantia nigra. In Progressive Supranuclear Palsy (PSP), the sign is attributed to the deposition of tau protein and iron in the substantia nigra. Early-onset levodopa-responsive Parkinsonism, a condition associated with mutations in the PANK2 gene, also exhibits the Eye of the Tiger sign due to iron accumulation in the substantia nigra.

**Why Each Wrong Option is Incorrect**
**Option A:** Hallervorden-Spatz syndrome is a correct association, but the question asks for all possible conditions, so this option is incomplete.
**Option B:** Progressive Supranuclear Palsy is also a correct association, but like Option A, it is incomplete.
**Option C:** Early-onset levodopa-responsive Parkinsonism is a correct association, but again, it is incomplete as it does not include the other two conditions.

**Clinical Pearl / High-Yield Fact**
The Eye of the Tiger sign is a valuable radiological clue in the diagnosis of neurodegenerative disorders, particularly in conditions associated with iron deposition and gliosis in the substantia nigra. This sign can help differentiate between various parkinsonian syndromes and guide further diagnostic workup.

**✓ Correct Answer: D. All of the above**