I believe the correct answer from the choices listed above is option B. The number and location of bones of many fossil vertebrates are similar to those in living vertebrates. This is evidence in support of common descent. Hope this answers the question.
Spicules are structural elements found in most sponges. They provide structural support and deter predators. Large spicules that are visible to the naked eye are referred to as megascleres, while smaller, microscopic ones are termed microscleres.