Fehling's reagent is used for testing :

Options

A. reducing sugars
B. non-reducing sugars
C. stereoisomerism
D. asymmetry of carbon atoms

Explanation

**Step-by-Step Solution:**

1. **Understanding Fehling's Reagent**: Fehling's reagent is a chemical solution used primarily in organic chemistry to test for the presence of certain types of sugars.

2. **Identifying the Function of Fehling's Reagent**: It is specifically used to differentiate between reducing and non-reducing sugars. Reducing sugars can donate electrons, which is a key characteristic that Fehling's reagent tests for.

3. **Recognizing Reducing Sugars**: Reducing sugars contain an aldehyde group or a ketone group that can be oxidized. Common examples of reducing sugars include glucose and fructose.

4. **Testing Procedure**: When a reducing sugar is present, Fehling's reagent will produce a color change, typically resulting in a red precipitate of copper(I) oxide (Cu2O) upon heating.

5. **Eliminating Other Options**:
- **Non-reducing Sugars**: Non-reducing sugars, such as sucrose, do not react with Fehling's reagent and are tested using other reagents like Tollens' reagent.
- **Stereoisomerism and Asymmetry of Carbon Atoms**: These concepts relate to the spatial arrangement of atoms in molecules and do not pertain to the testing of sugars with Fehling's reagent.

6. **Conclusion**: Based on the above points, the correct answer to the question is that Fehling's reagent is used for testing reducing sugars.

**Final Answer**: Reducing sugars.

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