One example of a nutrient in its reduced form is

Options

A. (a) carbon in `CO_(2)`
B. (b) hydrogen in `H_(2)O`
C. (c) nitrogen in `NH_(3)`
D. (d) sulphur in sulphate

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for an example of a nutrient that is in its reduced form. Nutrients can exist in various oxidation states, and the reduced form typically refers to a state where the nutrient has gained electrons.

2. **Analyzing the Options**:
- **Option A: Carbon in Carbon Dioxide**: In carbon dioxide (CO2), carbon is in a fully oxidized state, not reduced.
- **Option B: Hydrogen in Water**: In water (H2O), hydrogen is not in a reduced form; it is bonded with oxygen.
- **Option C: Nitrogen in Ammonia**: Ammonia (NH3) is a reduced form of nitrogen. Here, nitrogen has gained electrons compared to its state in nitrogen gas (N2).
- **Option D: Sulphur in Sulphate**: In sulphate (SO4^2-), sulphur is in an oxidized state.

3. **Identifying the Correct Answer**: Among the options, ammonia (NH3) is the only compound where nitrogen is in a reduced form. Therefore, the correct answer is option C.

4. **Conclusion**: The nutrient in its reduced form is nitrogen, specifically in the form of ammonia (NH3).

**Final Statement**: Hence, the correct answer is option C, Nitrogen in Ammonia.

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