**Core Concept**
Jumping genes are mobile genetic elements that can change their location within a genome, often leading to genetic variation and influencing gene expression. They are also known as transposons, which are DNA sequences that can move from one location to another within a genome.

**Why the Correct Answer is Right**
Transposons, or jumping genes, are characterized by their ability to transpose themselves from one location to another within a genome. This process involves the enzyme transposase, which catalyzes the movement of the transposon. Transposons can be found in both prokaryotic and eukaryotic genomes and can have various effects on gene expression, including activating or silencing genes.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because while DNA polymerase is an enzyme involved in DNA replication, it is not directly involved in the movement of jumping genes.
* **Option B:** This option is incorrect because a gene is a unit of heredity that carries information from one generation to the next, whereas jumping genes are mobile genetic elements that can change their location within a genome.
* **Option C:** This option is incorrect because a plasmid is a small, self-replicating circular DNA molecule found in bacteria, whereas jumping genes are mobile genetic elements found in both prokaryotic and eukaryotic genomes.

**Clinical Pearl / High-Yield Fact**
It's worth noting that jumping genes have been implicated in various diseases, including cancer, where they can contribute to genetic instability and tumor progression. Understanding the mechanisms of jumping genes is important for developing new therapeutic strategies to target these elements.

**Correct Answer:** C. Transposons.