Notochord is found only in the tail of Larva in -

Options

A. All chordata
B. Hemichordata
C. Urochordata
D. Cephalochordata

Answer

To solve the question "Notochord is found only in the tail of Larva in -", we need to analyze the options provided and understand the characteristics of each group mentioned.

### Step-by-Step Solution:

1. **Understanding Notochord**: The notochord is a flexible rod-shaped structure that is a defining characteristic of the phylum Chordata. It is typically present during the embryonic stage of all chordates.

2. **Analyzing the Options**:
- **Option 1: Al-Cordata**: This option is incorrect because all chordates possess a notochord at some stage in their life cycle, not just in the tail of the larva.

- **Option 2: Hemichordata**: This option is also incorrect. Hemichordates are worm-like marine animals that do not possess a true notochord; they have a structure called a stomochord, which is not the same as a notochord.

- **Option 3: Urochordata**: This is the correct option. In Urochordata (also known as Tunicates), the notochord is present only in the larval stage and is located in the tail. As they mature, the notochord is lost.

- **Option 4: Cephalochordata**: This option is incorrect as well. In Cephalochordates, the notochord extends from the tail to the anterior part of the body, meaning it is not restricted to just the tail.

3. **Conclusion**: Based on the analysis, the correct answer is **Urochordata** (Option 3), as the notochord is found only in the tail of the larva in this group.

### Final Answer:
**Urochordata** (Option 3)