They are invertebrates. They have radial symmetry. They are made of one segment. They have an open circulatory system.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which conclusion can be made about earthworms because they do not have an internal skeleton?
Possibilities:
- They are invertebrates.
- They have radial symmetry.
- They are made of one segment.
- They have an open circulatory system.

They are invertebrates.