A root parasite is

Options

A. Loranthus
B. Rafflesia
C. Viscum
D. Cuscuta

Answer

To answer the question "A root parasite is," we need to understand what a root parasite is and then evaluate the options provided.

### Step-by-Step Solution:

1. **Definition of Root Parasite**:
- A root parasite is an organism that lives in the roots of a host plant. It derives water, minerals, and food (such as starch and carbohydrates) from the host plant.

2. **Evaluate the Options**:
- **Option 1: Loranthus**: This is not a root parasite; it is a partial stem parasite that lives on the stem of the host plant and derives water and minerals but not food.
- **Option 2: Reptilacea**: This is a root parasite. It is a complete root parasite that depends on the host plant's roots for water, minerals, and food.
- **Option 3: Viscum**: Similar to Loranthus, Viscum is also a partial stem parasite. It lives on the stem and extracts water and minerals but does not derive food from the host.
- **Option 4: Cascada**: This is a complete stem parasite, meaning it relies on the stem of the host for its needs, not the roots.

3. **Conclusion**:
- Based on the definitions and evaluations of the options, the correct answer to the question "A root parasite is" would be **Option 2: Reptilacea**.

### Final Answer:
**A root parasite is Reptilacea (Option 2).**

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