**Core Concept**
Transfer of genetic material by bacteriophage is a process known as transduction, where a bacteriophage (a virus that infects bacteria) accidentally picks up bacterial DNA and transfers it to a new host bacterium. This process can lead to the exchange of genetic material between bacteria, resulting in the spread of antibiotic resistance and other traits.

**Why the Correct Answer is Right**
Transduction occurs when a bacteriophage, typically a lytic phage, enters a bacterium and injects its viral DNA. However, in some cases, the phage may also pick up bacterial DNA, which is then transferred to a new host bacterium when the phage infects it. This process is facilitated by the phage's ability to package and transfer DNA fragments, often resulting in the transfer of specific genes or genetic elements. The transferred DNA can then be integrated into the host bacterium's genome, leading to changes in its phenotype.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not describe a known mechanism of genetic transfer. While conjugation and transformation are both mechanisms of genetic transfer, they do not involve bacteriophages.
* **Option B:** This option is incorrect because it describes a process called gene editing, which involves the use of specific enzymes to modify DNA sequences. While gene editing is a powerful tool for manipulating genetic material, it is not related to the transfer of genetic material by bacteriophages.
* **Option C:** This option is incorrect because it describes a process called horizontal gene transfer, which is a broad term that encompasses various mechanisms of genetic transfer between organisms. While transduction is a type of horizontal gene transfer, the term is too general to be correct.

**Clinical Pearl / High-Yield Fact**
Transduction is an important mechanism of antibiotic resistance spread among bacteria, and understanding this process can help inform strategies for controlling the spread of resistance.

**Correct Answer: C. Transduction. Transfer of genetic material by bacteriophage.**