What did Wallace conclude from observing that the bones in manatee flippers look similar to the bones in a human arm and hand?

Manatee flipper

Question 5 options:

Manatee finger bones must have an important function, necessary for the animal's survival.

Manatees' arm and finger bones are evidence that manatees share a common ancestor with land mammals.

Manatees use their flippers like humans use their hands.

Manatees were specially created in their current form, including the arm and finger bones inside their flippers.