This living jumping spider and this fossil eurypterid both have body structures called chelicerae. Chelicerae are a body structure used for eating. What best explains why both species have chelicerae?

This living jumping spider and this fossil eurypterid both have body structures called chelicerae. Chelicerae are a body structure used for eating. What best explains why both species have chelicerae?
a
It is impossible to say. Fossils are very old; therefore, we cannot make observations of the eurypterid’s ancestors, and we cannot explain its body structures.
b
The jumping spider and eurypterid are different species, so they must not share an ancestor population. They inherited chelicerae from separate ancestor populations.
c
All species have their own specific body structures, so it is a coincidence that this jumping spider and eurypterid each happen to have a chelicerae structure.
d
The jumping spider and eurypterid both share the same ancestor population that had chelicerae. They inherited this structure from the ancestor population.