## Core Concept
Gene therapy involves introducing, removing, or changing genetic material within a patient's cells to fight or prevent disease. Various methods are employed to introduce genes into target cells, including viral vectors, non-viral vectors, and physical methods.

## Why the Correct Answer is Right
The correct answer, , is a method that does not belong to the common techniques used for gene introduction. Common methods include:
- **Electroporation**: Uses electrical pulses to create temporary holes in cell membranes, allowing DNA to enter.
- **Microinjection**: Directly injects DNA into cells using a fine needle.
- **Viral Vectors**: Utilizes viruses to deliver genetic material into cells.
- **Lipofection**: Employs lipids to fuse with cell membranes and deliver DNA.

## Why Each Wrong Option is Incorrect
- **Option A:** Electroporation is indeed a method used to introduce genes into cells by creating temporary pores in the cell membrane.
- **Option B:** Microinjection is a technique where DNA is directly injected into cells, making it a valid method.
- **Option D:** Viral vectors are widely used for gene delivery, taking advantage of a virus's natural ability to enter cells.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the efficiency and applicability of these methods vary widely depending on the cell type and the specific gene being introduced. For example, viral vectors are highly efficient but can provoke immune responses.

## Correct Answer: .