Answer:
b. pseudocoelom
Explanation:
A pseudocoelom is a false body cavity of some invertebrates which occupies the space localized between the mesoderm and the endoderm of the gut. This false cavity is found in nematodes.
Arthropods exhibit:
1- Bilateral symmetry because both opposite sides of the body are similar,
2- they are protostomes because the blastopore becomes the mouth during embryonic development,
3- they have true tissues because tissues are formed by groups of cells which share a common function, and finally,
4-arthropods are triploblastic because they are formed by three germ embryonic layers (endoderm, mesoderm and ectoderm).
