10. This octopus and this surf clam both have a body structure called a mantle, which covers their soft bodies. However,
the mantle is shaped differently in the two species. The octopus's mantle has muscles that help the octopus swim. The
surf clam's mantle helps the clam build its shell. What most likely explains why both the octopus and surf clam have
mantles and why the mantles are different?