Pith and cortex do not differentiate in

Options

A. monocot stem
B. dicot stem
C. monocot root
D. dicot root

Explanation

To solve the question "Pith and cortex do not differentiate in," we need to analyze the options provided: monocot stem, dicot stem, monocot root, and dicot root.

### Step-by-Step Solution:

1. **Understand the Terms**:
- **Pith**: The central part of the stem or root, typically composed of parenchyma cells.
- **Cortex**: The outer layer of tissue in a stem or root, lying between the epidermis and the vascular tissue.

2. **Identify the Types of Plants**:
- **Monocots**: Plants with one seed leaf (cotyledon), such as grasses and lilies.
- **Dicots**: Plants with two seed leaves, such as roses and sunflowers.

3. **Examine Monocot Stem**:
- In monocot stems, the ground tissue is generally undifferentiated. This means that the pith and cortex are not distinctly separated or recognizable. The vascular bundles are scattered throughout the stem.

4. **Examine Dicot Stem**:
- In dicot stems, the pith and cortex are clearly differentiated. The vascular bundles are arranged in a ring, allowing for clear separation between these two tissues.

5. **Examine Monocot Root**:
- In monocot roots, the pith is present and can be differentiated from the cortex, although the arrangement may vary.

6. **Examine Dicot Root**:
- In dicot roots, the pith and cortex are also differentiated, similar to dicot stems.

7. **Conclusion**:
- Based on the analysis, the only option where pith and cortex do not differentiate is in the **monocot stem**.

### Final Answer:
The correct answer is **monocot stem**.