**Core Concept**
Genomic imprinting is an epigenetic phenomenon where the expression of a gene is influenced by its parental origin, leading to the silencing or activation of the gene based on whether it was inherited from the mother or father.

**Why the Correct Answer is Right**
Genomic imprinting is a crucial mechanism in the development and growth of organisms, particularly in mammals. It is essential for the proper functioning of genes involved in growth, development, and metabolism. Imprinted genes are typically involved in critical developmental processes, such as embryonic growth and brain development. For instance, the insulin-like growth factor 2 (IGF2) gene is imprinted in the placenta, ensuring proper fetal growth and development.

**Why Each Wrong Option is Incorrect**
* **Option A:** While genomic imprinting is a type of epigenetic modification, it is not the same as DNA methylation or histone modification, which are other forms of epigenetic regulation.
* **Option B:** Genomic imprinting is not a feature of viral infections, which can lead to epigenetic modifications through different mechanisms.
* **Option C:** Genetic mutations, such as point mutations or chromosomal rearrangements, can affect gene expression, but they are distinct from genomic imprinting.

**Clinical Pearl / High-Yield Fact**
A key example of genomic imprinting is the Angelman syndrome, a neurodevelopmental disorder caused by the loss of function of the maternally inherited UBE3A gene. This highlights the critical role of genomic imprinting in brain development and function.

**Correct Answer: C. Prader-Willi Syndrome**