Which of these is not a fruit?

Options

A. Walnut
B. Peach
C. Cauliflower
D. Pea

Explanation

To determine which of the given options is not a fruit, we will analyze each option based on the definition of a fruit and its characteristics.

### Step-by-Step Solution:

1. **Understanding the Definition of a Fruit**:
- A fruit is typically defined as the mature ovary of a flowering plant, usually containing seeds. It develops from the fertilized ovary after flowering.

2. **Analyzing the Options**:
- **Walnut**: This is a type of drupe (a fleshy fruit with a hard shell) that contains seeds. Therefore, walnut is a fruit.
- **Peach**: This is also a drupe, known for its sweet, fleshy exterior and a single seed inside. Hence, peach is a fruit.
- **Pea**: Peas are seeds that develop from the ovary of a pea flower. They are considered fruits because they contain seeds and develop from the flower's ovary.
- **Cauliflower**: This is a vegetable that belongs to the Brassicaceae family. It is made up of a cluster of undeveloped flower buds and does not develop from the ovary of a flower. Therefore, cauliflower is not a fruit.

3. **Conclusion**:
- Based on the analysis, the option that is not a fruit is **cauliflower**.

### Final Answer:
Cauliflower is not a fruit.

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