To determine the number of animals in the given list that are triploblastic, bilaterally symmetrical, and pseudocoelomate, we need to analyze the characteristics of each animal.

1. Ascaris:
- Ascaris is a roundworm that belongs to the phylum Nematoda.
- It is triploblastic, meaning it has three germ layers: ectoderm, mesoderm, and endoderm.
- It is bilaterally symmetrical, having a definite right and left side.
- It is pseudocoelomate, as it has a body cavity called a pseudocoelom that is partially lined by mesoderm.

2. Fasciola:
- Fasciola is a liver fluke that belongs to the phylum Platyhelminthes.
- It is triploblastic, having three germ layers.
- It is bilaterally symmetrical.
- It is acoelomate, meaning it lacks a body cavity.

3. Ancylostoma:
- Ancylostoma is a hookworm that belongs to the phylum Nematoda.
- It is triploblastic.
- It is bilaterally symmetrical.
- It is pseudocoelomate.

4. Taenia:
- Taenia is a tapeworm that belongs to the phylum Platyhelminthes.
- It is triploblastic.
- It is bilaterally symmetrical.
- It is acoelomate.

5. Neries:
- It seems there might be a typo in the given list, as "Neries" is not a recognized animal. It is likely a misspelling of "Nereis," which is a marine polychaete worm.
- Nereis is triploblastic.
- It is bilaterally symmetrical.
- It is coelomate, meaning it has a true body cavity called a coelom.

6. Wuchereria:
- Wuchereria is a filarial worm that belongs to the phylum Nematoda.
- It is triploblastic.
- It is bilaterally symmetrical.
- It is pseudocoelomate.

7. Pheretima:
- Pheretima, also known as earthworm, belongs to the phylum Annelida.
- It is triploblastic.
- It is bilaterally symmetrical.
- It is coelomate.

Based on the analysis above, we can conclude that out of the given animals, three animals are triploblastic, bilaterally symmetrical, and pseudocoelomate. Therefore, the correct answer is option 'B' - Three.

Animals belong to the phylum Aschelminthes (Nematoda) are triploblastic, bilaterally symmetrical and pseudocoelomate, e.g., Ascaris (round worm), Wuchereria (filaria worm), Ancylostoma (hookworm).