A barrier reef develops

Options

A. Near sea shore
B. Deep in sea
C. At some distance from sea shore
D. Around a lagoon.

Answer

### Step-by-Step Solution:

1. **Understanding Barrier Reefs**:
- Barrier reefs are a type of coral reef that is typically found at some distance from the shore. They are composed of coral organisms, primarily belonging to the class Anthozoa within the phylum Cnidaria.

2. **Identifying the Location of Barrier Reefs**:
- Barrier reefs are not located near the shore (this would be a coastal reef) nor are they found deep in the sea. They require a specific environment to thrive, which includes sunlight for the photosynthetic dinoflagellates that live in symbiosis with the corals.

3. **Analyzing the Options**:
- **Option A**: "They are developed as near seashore" - Incorrect, as barrier reefs are not coastal reefs.
- **Option B**: "Deep in sea" - Incorrect, as corals need light for photosynthesis and cannot thrive in deep waters.
- **Option C**: "At some distance from seashore" - Correct, as barrier reefs are indeed found at a distance from the shore, separated by a lagoon or water body.
- **Option D**: "Around the lagoon" - Incorrect, as this describes atolls, which are different from barrier reefs.

4. **Conclusion**:
- The correct answer is that barrier reefs develop at some distance from the seashore.