Large medulla is immediately surrounded by many protoxylem groups in the primary structure of

Options

A. Dicot root
B. Monocot root
C. Monocot stem
D. Dicot stem

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the primary structure of a plant where a large medulla is surrounded by many protoxylem groups. We need to identify which plant structure this refers to.

2. **Identifying Plant Structures**: In flowering plants, the primary structure can refer to various parts such as roots, stems, or leaves. The medulla refers to the central part of a stem or root.

3. **Defining Medulla and Protoxylem**: The medulla is typically associated with the pith of the plant, which is the central tissue. Protoxylem refers to the first-formed xylem tissue that is responsible for water transport.

4. **Analyzing the Context**: In the context of flowering plants, the presence of a large medulla surrounded by protoxylem groups is characteristic of the primary structure of a dicot stem.

5. **Conclusion**: Therefore, the primary structure being referred to in the question is the primary structure of a dicot stem, where the large medulla (pith) is surrounded by protoxylem groups.

**Final Answer**: The primary structure of a dicot stem.

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