Meaningful girdling (Ringing) experiments cannot be done on sugarcane because

Options

A. its phloem is situated interior to xylem
B. its stem surface is covered with waxy coating
C. its vascular bundles are not present in a ring
D. its stem is thin

Explanation

### Step-by-Step Text Solution

1. **Understanding Girdling (Ringing) Experiment**:
- The girdling experiment involves removing a ring of bark from the stem of a plant. This process removes the phloem, which is responsible for transporting nutrients (sugars) downward from the leaves to the roots.

2. **Consequences of Girdling**:
- When the phloem is removed, nutrients accumulate above the girdle, leading to swelling of the bark and the formation of adventitious roots. However, the tissues below the girdle will not receive food, causing them to shrivel and eventually die due to starvation.

3. **Requirement for Girdling**:
- For a successful girdling experiment, a distinct ring arrangement of vascular bundles (xylem and phloem) is necessary. This allows for the effective removal of the phloem without affecting the xylem.

4. **Vascular Bundle Arrangement in Plants**:
- In dicots, vascular bundles are arranged in a ring formation, with phloem on the outer side and xylem on the inner side. This arrangement facilitates the girdling process.
- In contrast, monocots, such as sugarcane, have vascular bundles that are scattered throughout the stem. This scattered arrangement means that there is no distinct ring of phloem that can be removed.

5. **Conclusion**:
- Since sugarcane is a monocot and lacks the necessary ring arrangement of vascular bundles, meaningful girdling experiments cannot be performed on it. Therefore, the girdling experiment is ineffective and meaningless in the case of sugarcane.

### Final Answer
Meaningful girdling (ringing) experiments cannot be done on sugarcane because it is a monocot with scattered vascular bundles, lacking the distinct ring arrangement necessary for the experiment.

---