Cnidaria is characterised by

Options

A. Nematoblasts
B. Coelenteron
C. Tissue level of organisation
D. All the above.

Answer

### Step-by-Step Solution:

1. **Understanding Cnidaria**: Cnidaria is a phylum of animals that includes jellyfish, corals, and sea anemones. They are primarily aquatic and exhibit a range of body forms.

2. **Key Characteristics**:
- **Nematoblasts (or Nematocysts)**: These are specialized cells found in cnidarians that contain stinging structures. They are used for capturing prey and defense against predators.
- **Cilantro (Cilentrons)**: This term likely refers to the presence of cilia in certain life stages of cnidarians, which helps in locomotion and feeding.
- **Tissue Level of Organization**: Cnidarians are diploblastic, meaning they have two germ layers (ectoderm and endoderm) and possess a simple tissue organization.

3. **Evaluating the Options**:
- The first option mentions **pneumatoblasts**, which are indeed present in cnidarians as stinging cells.
- The second option refers to **cilantro**, which is relevant to their locomotion and feeding mechanisms.
- The third option states **tissue level of organization**, confirming that cnidarians are diploblastic.
- The last option is **all of the above**, which suggests that all the previous statements are correct.

4. **Conclusion**: Since all the mentioned characteristics (nematoblasts, cilantro, and tissue level of organization) are true for cnidarians, the correct answer to the question is **all of the above**.

### Final Answer:
Cnidaria is characterized by **all of the above**: nematoblasts, cilantro, and tissue level of organization.

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