Which of the following processes allows a host bacterium to gain genetic material from a bacteriophage?

Transduction is the correct answer because it is a specific process in which a bacteriophage, a type of virus that infects bacteria, transfers genetic material from one bacterium to another. In transduction, a bacteriophage infects a host bacterium and, during the replication process, may accidentally incorporate fragments of the host's DNA into its own viral genetic material. When this bacteriophage infects a new host bacterium, it can introduce the previously acquired genetic material into that new bacterium's genome. This mechanism is a significant means of horizontal gene transfer among bacteria, allowing for genetic diversity and the potential acquisition of beneficial traits, such as antibiotic resistance.

Other processes mentioned in the choices have distinct functions. Replication refers to the process by which a bacterium duplicates its own DNA to reproduce, so it does not involve the transfer of genetic material from a phage. Transformation is the uptake of free DNA from the environment by a bacterium, which is another method of horizontal gene transfer, but does not involve a bacteriophage. Transcription is the process by which DNA is converted into RNA, which is part of gene expression, but it does not relate to genetic material transfer from one cell to another.