Which acid is secreted by the stomach wall to activate digestive enzymes?

Options

A. Lactic acid
B. Hydrochloric acid
C. Sulphuric acid
D. Tartaric acid

Explanation

To answer the question "Which acid is secreted by the stomach wall to activate digestive enzymes?", we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Function of Stomach Acid**: The stomach secretes acid to aid in digestion. This acid helps to create an acidic environment that is necessary for the activation of digestive enzymes.

2. **Know the Types of Acids**: We have several options to consider: lactic acid, hydrochloric acid, sulphuric acid, and tartaric acid.

3. **Evaluate Each Option**:
- **Lactic Acid**: This acid is produced in muscles during anaerobic respiration and is not secreted by the stomach.
- **Hydrochloric Acid (HCl)**: This is the primary acid secreted by the stomach lining. It helps to activate pepsinogen into pepsin, which is crucial for protein digestion.
- **Sulphuric Acid**: This acid is not produced in the human body and does not play a role in digestion.
- **Tartaric Acid**: This acid is found in certain plants and is not involved in the digestive processes of the stomach.

4. **Conclusion**: Based on the evaluation, hydrochloric acid is the correct answer as it is secreted by the stomach wall to activate digestive enzymes.

### Final Answer:
The acid secreted by the stomach wall to activate digestive enzymes is **Hydrochloric Acid**.

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