Bacteriophages are

Options

A. viruses that infect bacteria
B. bacteria that infect virus
C. bacteria that infect other bacteria
D. none of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Bacteriophages**: Begin by defining what bacteriophages are. Bacteriophages are a type of virus specifically known for their ability to infect bacteria.

2. **Identifying the Nature of Bacteriophages**: Bacteriophages require a host to replicate and survive. In this case, the host is bacteria. Without a host, bacteriophages cannot carry out life processes, as they are considered non-living entities when outside a host.

3. **Examples of Bacteriophages**: Some common examples of bacteriophages include T4, T2, and Lambda. These are well-studied bacteriophages that serve as models for understanding how viruses interact with bacterial cells.

4. **Evaluating the Options**: Now, let's look at the options provided:
- A. Viruses that infect bacteria
- B. Bacteria that infect virus
- C. Bacteria that infect other bacteria
- D. None of the above

5. **Selecting the Correct Answer**: Based on the definition and characteristics of bacteriophages, the correct answer is option A, which states that bacteriophages are viruses that infect bacteria.

**Final Answer**: A. Viruses that infect bacteria.

---