An animal pops out its stomach through its mouth to eat the soft material of those animals which are covered by hard shell of calcium carbonate. After opening the shell and eating the soft material the stomach goes back into the body of the animal to slowly digest the food. The name of this animal is

Options

A. crocodile
B. Octopus
C. tortoise
D. starfish

Explanation

To solve the question regarding the animal that can pop its stomach out through its mouth to eat soft material from shelled animals, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Behavior**: The question describes an animal that can extend its stomach outside its body to consume prey that has a hard shell made of calcium carbonate. This behavior is quite unique and not common among many animals.

2. **Identifying the Prey**: The prey mentioned is covered by a hard shell of calcium carbonate, which is characteristic of certain marine animals like mollusks (e.g., clams, oysters).

3. **Analyzing the Options**: The options given are crocodile, octopus, tortoise, and starfish. We need to determine which of these animals has the ability to extend its stomach to digest food externally.

4. **Evaluating Each Option**:
- **Crocodile**: This is a reptile that does not exhibit this behavior.
- **Octopus**: While octopuses are known for their intelligence and ability to manipulate their environment, they do not pop their stomach out to eat.
- **Tortoise**: Tortoises are land reptiles and do not have this feeding mechanism.
- **Starfish**: Starfish (or sea stars) are echinoderms that can indeed extend their stomachs out of their bodies to digest prey, particularly those with hard shells.

5. **Conclusion**: Based on the unique feeding mechanism described, the animal that fits this behavior is the starfish. They can evert (turn inside out) their stomachs to digest food externally before retracting it back into their bodies.

### Final Answer: Starfish

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