Seed bud is

Options

A. Plumule
B. Tegmen
C. Ovule
D. Mesocotyl

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks what the term "seed bud" refers to among the given options: plumule, tegmen, ovule, or mesocotyle.

2. **Analyzing the Options**:
- **Plumule**: This is the primary bud of the plant embryo, located at the apex of the hypocotyl. It consists of the first leaves and the shoot. However, it does not directly relate to the term "seed bud."
- **Tegmen**: This is the inner covering of the seed, which is protective in function. It does not relate to the concept of a seed bud.
- **Ovule**: The ovule is the part of the plant that develops into the seed after fertilization. This is the most relevant option as it directly correlates with the term "seed bud."
- **Mesocotyle**: This is the portion of the axis between the cotyledon and the coleoptile in grass seedlings. It does not pertain to the seed bud either.

3. **Conclusion**: After analyzing all the options, the correct answer is that the seed bud is the **ovule**, as it is the part that develops into the seed.

### Final Answer:
The seed bud is the **ovule**.

---