Analogous structures in living organisms are a clue to common ancestry

What do you think the answer is, and why?

While we're happy to help, we won't give you the answer. You have to do the work, it's your homework, and you'll be the one graded on it, and tested on it. You have to learn to figure this out.

So what do you think? Back up your answer with research you've done, and facts. Then you'll find your answer. :)