Visceral mass is characteristic of

Options

A. arthropods
B. molluscs
C. echinoderms
D. All of these

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the characteristic feature known as "visceral mass" and which group of animals it is associated with.

2. **Analyzing the Options**: The options provided are:
- A) Arthropods
- B) Mollusks
- C) Echinoderms
- D) All of these

3. **Defining Visceral Mass**: The visceral mass is a term used to describe a part of the anatomy in certain animals, particularly mollusks. It refers to the soft, internal organs of the animal, which include the digestive, reproductive, excretory, and respiratory systems.

4. **Identifying the Correct Group**:
- **Mollusks**: They are characterized by having a visceral mass that contains most of their internal organs. This mass is usually covered by a mantle and may be enclosed in a shell.
- **Arthropods**: They do not have a visceral mass; instead, they have a segmented body and jointed appendages.
- **Echinoderms**: They also do not possess a visceral mass in the same way mollusks do; they have a unique body structure and a skeleton made of calcium carbonate.

5. **Conclusion**: Based on the definitions and characteristics, the visceral mass is a distinctive feature of **mollusks**. Therefore, the correct answer is **B) Mollusks**.

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