Which of the following statements are correct regarding secretion oxyntic cells?
(i) It denatures proteins and softens fibrous connective tissues in the blood.
(ii) It activates rennin.
(iii) It has a role in maturation of RBCs.
(iv) It activates trypsin.

Options

A. (a) i and iv
B. (b) ii, iii and iv
C. (c) i, ii and iii
D. (d) i, ii, iv

Explanation

To determine which statements are correct regarding the secretion of oxyntic cells, we will analyze each statement based on the functions of the substances secreted by these cells.

### Step-by-Step Solution:

1. **Identify the secretion of oxyntic cells**: Oxyntic cells, also known as parietal cells, are located in the gastric glands of the stomach. They primarily secrete hydrochloric acid (HCl) and intrinsic factor.

2. **Evaluate Statement (i)**: "It denatures proteins and softens fibrous connective tissues in the blood."
- **Analysis**: Hydrochloric acid (HCl) does denature proteins and helps soften fibrous connective tissues. This statement is **correct**.

3. **Evaluate Statement (ii)**: "It activates rennin."
- **Analysis**: HCl activates rennin, an enzyme that helps digest milk proteins in infants. This statement is also **correct**.

4. **Evaluate Statement (iii)**: "It has a role in maturation of RBCs."
- **Analysis**: The intrinsic factor secreted by oxyntic cells is essential for the absorption of vitamin B12, which is crucial for the maturation of red blood cells (RBCs). Therefore, this statement is **correct**.

5. **Evaluate Statement (iv)**: "It activates trypsin."
- **Analysis**: HCl does not activate trypsin. Trypsin is activated by enterokinase in the intestinal juice. This statement is **incorrect**.

6. **Conclusion**: Based on the evaluations:
- Statements (i), (ii), and (iii) are correct.
- Statement (iv) is incorrect.

Thus, the correct answer is that statements 1, 2, and 3 are correct regarding the secretion of oxyntic cells.

### Final Answer:
The correct answer is **Option C: 1, 2, and 3 are correct statements.**

---