Which of the following does not pertain to a protostome?

Options

A. Spiral cleavage
B. Blastopore is associated with the anus
C. Schizocoelom
D. Annelids, arthropods, and molluscs

Explanation

To determine which of the following does not pertain to a protostome, we need to analyze the options provided:

1. **Spiral Cleavage**:
- In protostomes, the embryonic development includes a process called spiral cleavage. This means that the cells divide in a spiral arrangement. This characteristic is indeed associated with protostomes.

2. **Blastopore is Associated with the Anus**:
- In protostomes, the blastopore (the first opening that forms during embryonic development) develops into the mouth. If the blastopore becomes the anus instead, this characteristic pertains to deuterostomes, not protostomes. Therefore, this statement is incorrect for protostomes.

3. **Schizocoelom**:
- Protostomes typically have a schizocoelom, which is a type of body cavity formed by the splitting of the mesoderm. This is a characteristic of protostomes.

4. **Annelids, Arthropods, and Molluscs**:
- These groups of animals are classified as protostomes. Therefore, this statement is also true for protostomes.

Based on the analysis above, the statement that does not pertain to a protostome is: **"Blastopore is associated with the anus."**

### Summary of Steps:
1. Identify characteristics of protostomes.
2. Analyze each option against the characteristics of protostomes.
3. Determine which statement is incorrect for protostomes.