Which of the following is not correctly matched?

Options

A. Sodium and potassium-fluid balance of the body
B. Iron-bones and teeth
C. Calcium-bones and teeth
D. Fluorine-tooth decay

Explanation

To determine which of the following nutrient-function pairs is not correctly matched, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Identify the Nutrients and Their Functions**:
- We have four nutrients: Sodium (Na), Potassium (K), Iron (Fe), Calcium (Ca), and Fluorine (F).
- Each nutrient is paired with a specific function.

2. **Evaluate Each Nutrient-Function Pair**:
- **Sodium and Potassium**: The function given is fluid balance. This is correct, as both sodium and potassium play crucial roles in maintaining fluid balance in the body.
- **Iron**: The function given is maintaining the deficiency of anemia. This is not correctly matched. Iron is essential for the formation of hemoglobin in red blood cells, and its deficiency leads to anemia, but it does not "maintain" anemia; rather, it prevents it.
- **Calcium**: The function given is keeping bones and teeth strong. This is correct, as calcium is vital for bone health and dental strength.
- **Fluorine**: The function given is preventing tooth decay. This is also correct, as fluorine helps in the remineralization of teeth and reduces the risk of cavities.

3. **Conclusion**:
- The only incorrect match is the one involving Iron. Therefore, the answer is **option B: Iron, maintaining deficiency of anemia**.

### Final Answer:
The nutrient-function pair that is not correctly matched is **Iron (Fe) and maintaining deficiency of anemia**.

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