The most characteristic feature of mollusca is the presence of :-

Options

A. Hard - body
B. Shell
C. Mantle
D. Foot

Answer

**Step-by-Step Solution:**

1. **Understanding Mollusca**: Begin by recognizing that mollusks are a diverse group of invertebrates that include snails, clams, octopuses, and squids. They are characterized by certain anatomical features.

2. **Evaluating the Options**: The question asks for the most characteristic feature of mollusks. We need to analyze each option provided.

3. **Option 1 - Hard Body**: The first option suggests that mollusks have a hard body. This is incorrect because mollusks are known for their soft bodies, which is a key feature of this phylum.

4. **Option 2 - Shell**: The second option mentions a shell. While many mollusks do have shells, not all do (e.g., octopuses). Therefore, while shells are common, they are not the most defining characteristic of the entire phylum.

5. **Option 3 - Mantle**: The third option refers to the mantle. This is indeed a defining feature of mollusks. The mantle is an extension of the body wall that covers the internal organs and is responsible for secreting the shell in those mollusks that possess one.

6. **Option 4 - Other Features**: The fourth option is not specified in the transcript, but it is implied that it is also incorrect.

7. **Conclusion**: After evaluating all options, the most characteristic feature of mollusks is the presence of the mantle. Therefore, the correct answer is option 3.

**Final Answer**: The most characteristic feature of mollusca is the presence of the mantle.

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