the derivatives of gluconic acid are used as a source of

Options

A. Calcium
B. Iron
C. Glucose
D. Fat

Answer

### Step-by-Step Solution:

1. **Understanding Gluconic Acid**:
- Gluconic acid is an organic acid that is produced by certain fungi, particularly Aspergillus and Mucor.
- It is derived from glucose through the process of oxidation.

2. **Identifying Derivatives**:
- Derivatives of gluconic acid are compounds that are chemically modified forms of gluconic acid.
- These derivatives can have various biological and chemical applications.

3. **Exploring the Options**:
- The question provides four options: calcium, iron, glucose, and fat.
- We need to determine which of these is a source derived from gluconic acid.

4. **Analyzing Each Option**:
- **Calcium**: Derivatives of gluconic acid are known to be a rich source of calcium. Calcium gluconate is a common derivative used in dietary supplements and medical applications.
- **Iron**: There is no significant relationship between gluconic acid derivatives and iron.
- **Glucose**: While gluconic acid is derived from glucose, it is not a derivative of gluconic acid.
- **Fat**: There is no direct connection between gluconic acid derivatives and fat.

5. **Conclusion**:
- Based on the analysis, the correct answer is that the derivatives of gluconic acid are used as a source of **calcium**.

### Final Answer:
The derivatives of gluconic acid are used as a source of **calcium**.

---