Which one is the largest root parasite ?

Options

A. Rafflesia
B. Monotropa
C. Arceuthobium
D. All the above

Answer

### Step-by-Step Solution:

1. **Understanding Root Parasites**:
- Root parasites are plants that derive nutrients from other plants, known as host plants. They attach themselves to the host and extract water and nutrients.

2. **Identifying the Largest Root Parasite**:
- Among various root parasites, we need to identify which one is the largest.

3. **Recognizing Rafflesia**:
- The largest root parasite is Rafflesia. It is known for its unique characteristics and size.

4. **Characteristics of Rafflesia**:
- Rafflesia has evolved to be completely stemless, rootless, and leafless. It does not have the typical structures found in most plants. Instead, it has thread-like structures that live inside the host plant.

5. **Host Plant**:
- Rafflesia typically grows on plants from the Wittaceae family, which is also known as the grape family.

6. **Flower of Rafflesia**:
- The only visible part of Rafflesia is its flower, which can reach up to one meter in diameter, making it one of the largest flowers in the plant kingdom.

7. **Conclusion**:
- Therefore, the correct answer to the question "Which one is the largest root parasite?" is **Rafflesia**.