Which of the following rays is used to keep food items free from bacteria ?

Options

A. X-rays
B. Gamma rays
C. UV rays
D. None

Explanation

To solve the question "Which of the following rays is used to keep food items free from bacteria?", we will analyze the options provided and determine which one is correct based on their properties and uses.

### Step-by-Step Solution:

1. **Identify the Options**: The options given are:
- A) X-rays
- B) Gamma rays
- C) UV rays (Ultraviolet rays)
- D) None of the above

2. **Understand the Purpose**: The question is asking which type of ray is specifically used to keep food items free from bacteria. This involves understanding how different types of rays interact with microorganisms.

3. **Analyze Each Option**:
- **X-rays**: These are high-energy electromagnetic waves primarily used in medical imaging. They do not have a significant effect on bacteria in food.
- **Gamma rays**: These are also high-energy rays, used in radiation therapy and sterilization processes. While they can kill bacteria, they are not commonly used for food preservation due to safety concerns.
- **UV rays**: Ultraviolet rays are known for their germicidal properties. They can effectively kill bacteria and viruses by damaging their DNA, making them a popular choice for disinfecting surfaces and water, as well as for food preservation.
- **None of the above**: This option implies that none of the listed rays are used for keeping food free from bacteria, which is not true in this case.

4. **Conclusion**: Based on the analysis, the most suitable option for keeping food items free from bacteria is **C) UV rays**. They are specifically used for their ability to kill pathogens and viruses.

### Final Answer:
The correct option is **C) UV rays**.

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