Which of the following is an example of aldopentose

Options

A. D-Ribose
B. Glyceraldehyde
C. Fructose
D. Erythrose

Explanation

To determine which of the following is an example of an aldopentose, we need to understand the definitions and characteristics of aldopentoses.

### Step-by-Step Solution:

1. **Definition of Aldopentose**:
- An aldopentose is a type of sugar (carbohydrate) that is an aldose and contains five carbon atoms. Aldoses are sugars that have an aldehyde group (-CHO) at one end of the molecule.

2. **Identifying Aldopentose**:
- We need to look for a sugar that has five carbon atoms and an aldehyde functional group.

3. **Examples of Sugars**:
- **D-Ribose**: This is a five-carbon sugar (C5H10O5) with an aldehyde group, making it an aldopentose.
- **Glyceraldehyde**: This is a three-carbon sugar (C3H6O3), which is an aldotriose, not an aldopentose.
- **Erythrose**: This is a four-carbon sugar (C4H8O4), which is an aldotetrose, not an aldopentose.
- **Hexose**: Sugars like glucose or fructose are six-carbon sugars (C6H12O6) and are not aldopentoses.

4. **Conclusion**:
- Among the options provided, D-Ribose is the only sugar that qualifies as an aldopentose because it has five carbons and an aldehyde group.

### Final Answer:
- The correct answer is **D-Ribose**.