**Core Concept**
Krabbe's disease is a rare, inherited disorder caused by a deficiency of a specific enzyme involved in the breakdown of fatty substances in the brain. This enzyme plays a crucial role in the normal functioning of the central nervous system (CNS).

**Why the Correct Answer is Right**
The correct answer is a lysosomal enzyme called galactocerebrosidase (GALC). GALC is responsible for breaking down galactosylceramide, a type of fatty substance found in the myelin sheath, which surrounds and protects nerve fibers in the CNS. A deficiency of GALC leads to an accumulation of toxic substances in the brain, causing damage to the myelin sheath and resulting in the characteristic symptoms of Krabbe's disease, such as muscle weakness, seizures, and developmental delays.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because alpha-L-iduronidase is the enzyme deficient in Hunter syndrome, a different genetic disorder.
* **Option B:** This option is incorrect because arylsulfatase A is the enzyme deficient in Metachromatic Leukodystrophy (MLD), another type of leukodystrophy.
* **Option C:** This option is incorrect because beta-glucocerebrosidase is the enzyme deficient in Gaucher's disease, a lysosomal storage disorder.

**Clinical Pearl / High-Yield Fact**
Krabbe's disease is a progressive and fatal disorder, with most patients dying in early childhood. Early diagnosis and treatment with hematopoietic stem cell transplantation may help slow disease progression.

**Correct Answer: C. Galactocerebrosidase (GALC)**