**Core Concept**
The Y-chromosome is one of the 23 pairs of chromosomes in humans, and its unique structure is due to its evolutionary history. The Y-chromosome is characterized by its short arm being significantly smaller than its long arm, which is a distinct feature among the human chromosomes.

**Why the Correct Answer is Right**
The Y-chromosome is classified as acrocentric because its centromere is located very close to the short arm, resulting in the long arm being significantly larger. This unique structure is due to the fact that the Y-chromosome has undergone a process called pericentric inversion, which has relocated the centromere to the short arm. As a result, the long arm of the Y-chromosome becomes the larger arm, making it acrocentric. This characteristic is essential for its role in sex determination and the regulation of male-specific genes.

**Why Each Wrong Option is Incorrect**
**Option A:** Telocentric chromosomes have their centromere located at the very end of the chromosome, which is not the case for the Y-chromosome.
**Option B:** Metacentric chromosomes have their centromere located in the middle, equidistant from the two arms, which is not true for the Y-chromosome.
**Option C:** Submetacentric chromosomes have their centromere located off-center, but closer to one arm than the other, which does not accurately describe the Y-chromosome.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the Y-chromosome's acrocentric structure is crucial for its role in sex determination and the regulation of male-specific genes, such as the SRY gene, which triggers testis development during embryogenesis.

**✓ Correct Answer: D. Acrocentric. The Y-chromosome is classified as acrocentric due to its unique centromere location.**