Reduced, discoid and underground stem is found in

Options

A. Ginger
B. Turmeric
C. Potato
D. Onion

Answer

To determine which plant has a reduced, discoid, and underground stem, we can analyze the options provided: ginger, turmeric, potato, and onion.

### Step-by-Step Solution:

1. **Identify the Plant Structures**:
- We need to understand the type of stem structures present in each of the options: ginger, turmeric, potato, and onion.

2. **Analyze Ginger**:
- Ginger has a rhizome, which is an underground stem. However, it is not discoid in shape. Therefore, ginger does not fit the criteria.

3. **Analyze Turmeric**:
- Similar to ginger, turmeric also has a rhizome as its underground stem. It is not discoid either. Thus, turmeric is also not the correct answer.

4. **Analyze Potato**:
- The potato has a tuber as its vegetative reproductive organ. Tubers are swollen structures that store nutrients but are not discoid in shape. Therefore, potato does not meet the criteria.

5. **Analyze Onion**:
- The onion has a bulb, which is a modified underground stem. The bulb has a discoid shape and is also located underground. This matches all the criteria of being reduced, discoid, and underground.

6. **Conclusion**:
- Based on the analysis, the correct answer is **onion** (Option D), as it possesses a reduced, discoid, and underground stem structure.

### Final Answer:
The reduced, discoid, and underground stem is found in **onion**.