The larva of Sycon is

Options

A. parenchymula
B. amphiblastula
C. redia
D. planula

Answer

To determine the larva of Sycon, we need to analyze the options provided and understand the characteristics of Sycon and its larval form.

### Step-by-Step Solution:

1. **Identify the Organism**:
- Sycon is a genus of calcareous sponges. These sponges belong to the phylum Porifera.

2. **Understand the Options**:
- The options given are:
- A) Parenchymula
- B) Amphiblastula
- C) Radia
- D) Planula

3. **Research Each Option**:
- **Parenchymula**: This larval form is typically associated with certain sponges, particularly those in the class Demospongiae, not specifically with Sycon.
- **Amphiblastula**: This is known to be the larval form of calcareous sponges, including Sycon. It is a free-swimming larva characterized by having two different types of cells.
- **Radia**: This larval form is associated with Fasciola hepatica, a liver fluke, not sponges.
- **Planula**: This is the larval form of cnidarians, such as corals and jellyfish, not sponges.

4. **Conclusion**:
- Based on the information gathered, the larva of Sycon is identified as **Amphiblastula**.

5. **Final Answer**:
- The correct answer is **B) Amphiblastula**.