**Core Concept**
Menke's Kinky hair syndrome is a rare genetic disorder characterized by progressive brain damage, failure to thrive, and distinctive kinky hair. This condition is caused by a defect in a specific ion transporter involved in copper metabolism.

**Why the Correct Answer is Right**
Menke's Kinky hair syndrome is primarily due to mutations in the ATP7A gene, which encodes a copper-transporting ATPase. This enzyme plays a crucial role in regulating copper levels in the body by exporting excess copper from the cells into the bloodstream. In patients with Menke's disease, this defective copper transporter leads to copper accumulation in the brain, liver, and other organs, causing the characteristic symptoms of the disease.

**Why Each Wrong Option is Incorrect**
**Option A:** The defect in Menke's disease is not related to a calcium transporter.
**Option C:** Zinc transporters are involved in the regulation of zinc levels in the body, but they are not associated with Menke's disease.
**Option D:** Selenium transporters are responsible for maintaining selenium levels in the body, and their dysfunction is not linked to Menke's disease.

**Clinical Pearl / High-Yield Fact**
Menke's disease is an X-linked recessive disorder, primarily affecting males, as they have only one X chromosome. Females can be carriers of the disease, but they are less likely to exhibit symptoms due to the presence of a second X chromosome with a normal copy of the ATP7A gene.

**✓ Correct Answer: B. Cu transporter**