From which of the following pepsin is secreted:

Options

A. Lungs
B. Stomach
C. Salivary gland
D. Sebaceous gland

Answer

**Step-by-Step Solution:**

1. **Understanding Pepsin**: Pepsin is an enzyme that plays a crucial role in the digestion of proteins in the stomach. It is not secreted in other organs like the lungs or salivary glands.

2. **Identifying the Source**: Pepsin is secreted in the stomach. Specifically, it is produced by the chief cells located in the gastric mucosa.

3. **Pepsinogen Activation**: The chief cells secrete an inactive precursor called pepsinogen. When pepsinogen comes into contact with hydrochloric acid (HCl) that is also secreted in the stomach, it is converted into its active form, pepsin.

4. **Conclusion**: Therefore, the correct answer to the question "From which of the following pepsin is secreted?" is the stomach.

5. **Eliminating Incorrect Options**:
- Lungs: Incorrect, as they do not secrete pepsin.
- Salivary Glands: Incorrect, as they secrete saliva, not pepsin.
- Sebaceous Glands: Incorrect, as they secrete sebum, not pepsin.

6. **Final Answer**: The correct answer is option 2, the stomach.

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