You have discovered an animal having haemocoel , open blood vascular system but lacks segmentation . It should be classified under

Options

A. 1)Annelida
B. 2)Arthropoda
C. 3)Mollusca
D. 4)Urochordata

Answer

To classify the discovered animal based on the given characteristics, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Characteristics of the Animal:**
- The animal has a **haemocoel**.
- It has an **open blood vascular system**.
- It **lacks segmentation** (unsegmented body).

2. **Evaluate the Options:**
- **Option A: Annelida**
- Annelids have a **coelom** (true body cavity).
- They possess a **closed blood vascular system**.
- They are **segmented**.
- **Conclusion:** This option does not match any of the criteria. **(Incorrect)**

- **Option B: Arthropoda**
- Arthropods have a **haemocoel**.
- They possess a **closed blood vascular system**.
- They are **segmented**.
- **Conclusion:** This option does not match the criteria of having an open blood vascular system and lacking segmentation. **(Incorrect)**

- **Option C: Mollusca**
- Mollusks have a **haemocoel**.
- They possess an **open blood vascular system**.
- They are generally **unsegmented**.
- **Conclusion:** This option matches all three criteria. **(Correct)**

- **Option D: Urochordata**
- Urochordates lack a true coelom.
- They are generally **unsegmented**.
- They possess an **open blood vascular system**.
- **Conclusion:** While they are unsegmented and have an open vascular system, they do not have a haemocoel. **(Incorrect)**

3. **Final Conclusion:**
- Based on the evaluation, the animal should be classified under **Mollusca** (Option C) as it matches all the given characteristics.