The characters given below are shown by
(i) Extracellular and intracellular digestion
(ii) Exclusively marine, radially symmetrical, diploblastic, tissue level of organisation
(iii) Bisexual, fertilisation external and indirect development
(iv) No asexual reproduction
(v) Presence of comb plates

Options

A. Cnidaria
B. Porifera
C. Ctenophora
D. none of these

Answer

To solve the question regarding the characters exhibited by a certain group of animals, we will analyze each of the given characteristics step by step and determine which phylum they correspond to. The options provided are Nidaria, Porifera, and Tenophora.

### Step-by-Step Solution:

1. **Analyze the Characteristics**:
- The characteristics given are:
(i) Extracellular and intracellular digestion
(ii) Exclusively marine, radially symmetrical, diploblastic, tissue level of organization
(iii) Bisexual, fertilization external and indirect development
(iv) No asexual reproduction
(v) Presence of comb plates

2. **Evaluate Each Option**:
- **Nidaria**:
- They are diploblastic and have a tissue level of organization.
- They can be bisexual, and fertilization can be external and indirect.
- However, they do not have comb plates; instead, they have stinging cells (cnidocytes).
- They can reproduce asexually (e.g., budding in some species).
- Conclusion: Nidaria does not fit all the characteristics.

- **Porifera**:
- They are primarily known for their porous structure and have a unique canal system for feeding.
- They do not exhibit true tissue organization and are not diploblastic.
- They can reproduce both sexually and asexually.
- Conclusion: Porifera does not fit the characteristics.

- **Tenophora**:
- They are exclusively marine, radially symmetrical, and diploblastic.
- They exhibit both extracellular and intracellular digestion.
- They are bisexual, and fertilization is external with indirect development.
- They do not reproduce asexually.
- They are characterized by the presence of comb plates (ctenes).
- Conclusion: Tenophora fits all the characteristics given.

3. **Final Conclusion**:
- Based on the analysis, the group of animals that exhibit all the given characteristics is **Tenophora**. Therefore, the correct answer is option C: Tenophora.