A gene gun or a biolistic particle delivery system, originally designed for plant transformation, is a device for delivering exogenous DNA (transgenes) to cells. The payload is an elemental particle of a heavy metal coated with DNA (typically plasmid DNA). This technique is often simply referred to as biolistics.

Introduction:
Biolistics, also known as the gene-gun method, is a technique used to introduce foreign DNA into cells. It involves the delivery of DNA-coated particles into the target cells using a high-pressure helium-driven device. This method has found applications in various fields, including plant transformation, pathogen vector control, and DNA fingerprinting. However, in this case, the correct answer is option 'D,' which states that biolistics is suitable for the transformation of plant cells.

Transformation of plant cells:
Plant transformation refers to the process of introducing foreign DNA into plant cells, which can lead to the expression of new traits in the transformed plant. Biolistics has been widely used as a tool for plant transformation due to its ability to deliver DNA into plant cells without the need for plant tissue culture, which is a time-consuming and labor-intensive process.

Advantages of biolistics in plant transformation:
1. No tissue culture requirement: Unlike other methods such as Agrobacterium-mediated transformation, biolistics can directly deliver DNA into intact plant tissues, eliminating the need for tissue culture.
2. High transformation efficiency: Biolistics can achieve a high transformation efficiency, meaning a significant proportion of the bombarded plant cells can successfully incorporate the foreign DNA.
3. Broad host range: Biolistics can be used for the transformation of a wide range of plant species, including monocots and dicots, woody plants, and even algae.
4. No species-specific tools: Unlike other methods that may require specific tools or vectors for different plant species, biolistics can be applied to various plants without the need for extensive modifications.
5. Stable integration: The foreign DNA introduced by biolistics can integrate into the plant genome, leading to stable inheritance of the desired traits in subsequent generations.

Conclusion:
In conclusion, biolistics, or the gene-gun method, is a valuable technique for the transformation of plant cells. It offers advantages such as high transformation efficiency, broad host range, and stable integration of foreign DNA. This method has revolutionized the field of plant biotechnology and has contributed to the development of genetically modified crops with improved traits.