Segmentation is found in :-

Options

A. Annelida , Arthropoda, Mollusca
B. Arthropoda, Mollusca, Echinoderms
C. Annelida, Arthropoda, Chordata
D. Arthropoda, Echinoderms, Chordata

Answer

To solve the question "Segmentation is found in:", we will analyze the given options step by step.

### Step 1: Understand Segmentation
Segmentation refers to the division of an organism's body into repeating units or segments. This characteristic is significant in various animal phyla.

### Step 2: Analyze Each Option
1. **Option 1: Annelida, Arthropoda, and Mollusca**
- **Annelida**: This phylum includes earthworms, which are known for their segmented bodies. So, segmentation is present here.
- **Arthropoda**: This phylum includes insects, arachnids, and crustaceans, which also exhibit segmentation in their body structure.
- **Mollusca**: This phylum includes snails, clams, and squids. Molluscs do not have a segmented body; they are unsegmented.
- **Conclusion**: This option is incorrect due to the presence of Mollusca.

2. **Option 2: Arthropoda, Mollusca, and Echinoderms**
- **Arthropoda**: As mentioned, they have segmented bodies.
- **Mollusca**: As previously discussed, they do not have segmentation.
- **Echinoderms**: This group includes starfish and sea urchins, which also do not exhibit segmentation.
- **Conclusion**: This option is incorrect due to the presence of Mollusca and Echinoderms.

3. **Option 3: Annelida, Arthropoda, and Chordata**
- **Annelida**: Segmented bodies (e.g., earthworms).
- **Arthropoda**: Segmented bodies (e.g., insects).
- **Chordata**: This phylum includes vertebrates, which also show segmentation in their body structure (e.g., vertebral column).
- **Conclusion**: This option is correct as all three groups exhibit segmentation.

4. **Option 4: Arthropoda, Echinoderm, and Chordata**
- **Arthropoda**: Segmented bodies.
- **Echinoderms**: Do not have segmentation.
- **Chordata**: Segmented bodies.
- **Conclusion**: This option is incorrect due to the presence of Echinoderms.

### Final Answer
The correct answer is **Option 3: Annelida, Arthropoda, and Chordata**, as all these groups exhibit segmentation.

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