Flatworms are devoid of

Options

A. Circulatory system
B. Repiratory system
C. Skeketal system
D. All of the above

Answer

### Step-by-Step Solution:

1. **Identify the Organisms**: Flatworms belong to the phylum Platyhelminthes. Examples include liver flukes and tapeworms (tinea).

2. **Understand Their Characteristics**: Flatworms are known to be triploblastic, meaning they have three germ layers: ectoderm, mesoderm, and endoderm.

3. **Examine the Organ Systems**:
- **Circulatory System**: Flatworms do not have a circulatory system. They rely on diffusion for the transport of nutrients and gases through their skin.
- **Respiratory System**: They also lack a respiratory system. Gas exchange occurs via diffusion through the skin, eliminating the need for specialized respiratory organs like lungs.
- **Skeletal System**: Flatworms do not possess a skeletal system. Their body is soft and lacks a hard outer skeleton. Instead, they have cilia on their surface that assist in locomotion.

4. **Conclusion**: Since flatworms are devoid of a circulatory system, respiratory system, and skeletal system, the correct answer to the question is that flatworms are devoid of all of the above.

### Final Answer:
Flatworms are devoid of the circulatory system, respiratory system, and skeletal system.