Which one of the following sets of monosaccharides forms sucrose ?

Options

A. `beta-D-`Glucopyranose and `alpha-D-`fructoranose
B. `alpha-D-`Glucopyranose and `beta-D-`fructopyranose
C. `alpha-D-`Galactopyranose and `alpha-D-`Glucopyranose
D. `alpha-D-`Glucopyranose and `beta-D-`fructofuranose

Explanation

To determine which set of monosaccharides forms sucrose, we need to identify the two monosaccharides that combine to create this disaccharide. Sucrose is composed of two specific monosaccharides: glucose and fructose.

### Step-by-Step Solution:

1. **Identify the Structure of Sucrose**:
- Sucrose is a disaccharide formed from two monosaccharides. It consists of a glucose unit and a fructose unit.

2. **Recognize the Types of Monosaccharides**:
- Glucose is a six-membered ring structure known as a pyranose.
- Fructose, on the other hand, is a five-membered ring structure known as a furanose.

3. **Determine the Specific Forms of Glucose and Fructose**:
- In the case of sucrose, glucose is typically in the alpha form (α-D-glucopyranose) and fructose is in the beta form (β-D-fructofuranose).

4. **Combine the Monosaccharides**:
- When glucose and fructose combine through a glycosidic bond, they form sucrose. The bond is formed between the anomeric carbon of glucose and the hydroxyl group of fructose.

5. **Conclusion**:
- Therefore, the correct set of monosaccharides that form sucrose is α-D-glucopyranose and β-D-fructofuranose.

### Final Answer:
The monosaccharides that form sucrose are α-D-glucopyranose and β-D-fructofuranose.