**Core Concept**
Epigenetic modifications refer to heritable changes in gene function that occur without altering the underlying DNA sequence. These modifications can affect gene expression and play a crucial role in various biological processes, including development, cell differentiation, and disease.

**Why the Correct Answer is Right**
High-Performance Liquid Chromatography (HPLC) is a technique used to separate, identify, and quantify the components of a mixture. While HPLC can detect changes in DNA structure, such as DNA fragmentation or degradation, it is not specifically designed to detect epigenetic modifications. Epigenetic modifications involve changes in DNA or histone proteins that do not alter the DNA sequence itself. HPLC cannot distinguish between these modifications.

**Why Each Wrong Option is Incorrect**
**Option B:** Methylation-specific PCR (MSP) is a technique used to detect DNA methylation, a type of epigenetic modification. MSP can specifically detect methylated DNA sequences, making it a useful tool for epigenetic analysis.

**Option C:** The Bisulphite method is another technique used to detect DNA methylation. Bisulphite treatment converts unmethylated cytosines to uracils, allowing for the specific detection of methylated DNA sequences.

**Option D:** ChIP-on-Chip (Chromatin Immunoprecipitation on Chip) is a technique used to study the interaction between proteins and DNA. ChIP-on-Chip can detect epigenetic modifications such as histone modifications and DNA methylation.

**Clinical Pearl / High-Yield Fact**
Epigenetic modifications can be influenced by environmental factors, such as diet and exposure to toxins. Understanding epigenetics is crucial for developing targeted therapies for diseases, such as cancer, where epigenetic modifications play a key role.

**Correct Answer Line**
✓ Correct Answer: A. HPLC.