**Core Concept**
Hurler syndrome is a genetic disorder characterized by the accumulation of glycosaminoglycans (GAGs) in various tissues due to a deficiency in a specific enzyme involved in GAG metabolism. This accumulation leads to cellular dysfunction and various clinical manifestations.

**Why the Correct Answer is Right**
The correct answer is **B. a-l-Iduronidase**, which is the enzyme responsible for breaking down dermatan sulfate and heparan sulfate, two types of GAGs. In Hurler syndrome, mutations in the IDUA gene lead to a deficiency of a-l-iduronidase, resulting in the accumulation of these GAGs in the lysosomes of cells. This accumulation causes cellular dysfunction, leading to the clinical manifestations of Hurler syndrome, such as clouded corneas, coarse facial features, and intellectual disability.

**Why Each Wrong Option is Incorrect**
**Option A:** Iduronate sulfatase is the enzyme deficient in Hunter syndrome, a different lysosomal storage disorder.

**Option C:** b-Galactosidase is the enzyme deficient in GM1 gangliosidosis, a different lysosomal storage disorder characterized by the accumulation of gangliosides.

**Option D:** Galactosamine 6-sulfatase is involved in the metabolism of keratan sulfate, a type of GAG, but is not associated with Hurler syndrome.

**Clinical Pearl / High-Yield Fact**
It's essential to note that Hurler syndrome is an autosomal recessive disorder, meaning that a child must inherit two copies of the mutated IDUA gene (one from each parent) to develop the condition. A-l-iduronidase activity can be measured in various tissues, including blood and fibroblasts, to confirm the diagnosis.

**✓ Correct Answer: B. a-l-Iduronidase**