Giving 100 points for an answer AND explanation. The image below compares the structure of a bat wing to that of a bird. Based on what you know about the classifications of these animals and the difference in the bone structure of their wings, which of the following is the most logical conclusion about their evolution?

Bat and bird wing bones and silhouettes are shown side-by-side. Each has a single 'upper arm' bone and two parallel 'lower arm' bones that attach to 'hand' bones. The bat wing has 4 long digits inside the wing and one outside the wing. The bird has three digits inside the wing. The bat wing's silhouette has skin stretched between the digits while the bird wing's silhouette has feathery edges.

They both descended from a recent common ancestor, making bats more closely related to birds than to other mammals.
They both inherited their wings from a common ancestor and then diverged in their other body characteristics.
They evolved from a wingless common ancestor and developed wings independent of each other.
They evolved from entirely different ancestors, but both developed wings in response to similar ecological conditions.