Hey there, I built this website for students studying for tough tests. I think everyone should get education for free, so that's why I made this site. But now, the way Google ranks websites changed, and not many people are visiting here. I use money from Google ads to keep this site running, but with less visitors, it's hard to do that anymore. If you like this website and want it to keep going, can you help out? Any support you give would be really appreciated. Thanks a lot for considering it.

You can send your support here : Buy Me A Coffee

Which of the following is not a characteristic of phylum echinodermata ?

A. They have a water vascular system.

B. They have an internal skeleton.

C. They are protostomes.

D. They have bilateral symmetry at larval stage.

Please do not use chat terms. Example: avoid using "grt" instead of "great".