**Core Concept**
Bacteriophages, also known as phages, are viruses that specifically infect bacteria. They are composed of a protein coat and a genetic material, either DNA or RNA, which replicates within the bacterial host. Phages play a crucial role in the regulation of bacterial populations and have potential applications in biotechnology and medicine.

**Why the Correct Answer is Right**
Phages are highly specific to their bacterial hosts, with some phages infecting a single bacterial species while others can infect multiple species. They can be used as tools for gene therapy, vaccine development, and as antibacterial agents. The lytic cycle of phages involves the replication of the viral genome, followed by the production of new phage particles, which eventually lyse the bacterial cell.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because bacteriophages can indeed be used as antibacterial agents, either through direct lytic action or by inducing the production of bacteriocins.
**Option B:** Incorrect because phages can be used for gene therapy by delivering therapeutic genes into bacterial cells.
**Option C:** Incorrect because the lytic cycle of phages is a crucial aspect of their life cycle, involving the replication of the viral genome and the production of new phage particles.

**Clinical Pearl / High-Yield Fact**
One of the most significant advantages of phage therapy is its potential to target antibiotic-resistant bacteria, making it an attractive alternative to traditional antibiotic treatments.

**Correct Answer:** D.