Which of the following are the reason (s) for Rheumatoid arthritis ? Choose the correct option.
(i) The ability to differentiate pathogens or foreign molecules from self cells increases.
(ii) Body attacks self cells.
(iii) More antibodies are produced in the body.
(iv) The ability to differentiate pathogens or foreign molecules from self cells is lost.

Options

A. I and II
B. II and IV
C. III and IV
D. I and III

Explanation

To solve the question regarding the reasons for Rheumatoid Arthritis, we will analyze each option provided and determine which statements are correct based on our understanding of the disease.

### Step-by-Step Solution:

1. **Understanding Rheumatoid Arthritis**:
- Rheumatoid Arthritis (RA) is an autoimmune disease where the immune system mistakenly attacks the body's own tissues, particularly the joints. This results in inflammation, pain, and swelling.

2. **Analyzing Option (i)**:
- "The ability to differentiate pathogens or foreign molecules from self cells increases."
- This statement is **incorrect**. In RA, the immune system loses its ability to differentiate between self and non-self cells, leading to the attack on self cells.

3. **Analyzing Option (ii)**:
- "Body attacks self cells."
- This statement is **correct**. In RA, the immune system indeed attacks the body’s own cells, particularly in the joints.

4. **Analyzing Option (iii)**:
- "More antibodies are produced in the body."
- This statement is **not directly applicable**. While antibodies may be present, the primary issue in RA is the destruction of self cells rather than an increase in antibody production.

5. **Analyzing Option (iv)**:
- "The ability to differentiate pathogens or foreign molecules from self cells is lost."
- This statement is **correct**. In RA, the immune system loses its ability to distinguish between self and non-self, which leads to the autoimmune response.

6. **Conclusion**:
- The correct options that describe the reasons for Rheumatoid Arthritis are (ii) "Body attacks self cells" and (iv) "The ability to differentiate pathogens or foreign molecules from self cells is lost."

### Final Answer:
The correct options are (ii) and (iv).

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