I think it’s an compound sentence :) sorry If I’m wrong!
You did not provide the remaining sentences, but the first sentence provided The coast of Florida is home to many unique sea creatures like the manatee does not need revision for redundancies because it is correct.
Your tone
Let's look at the other choices first. Your credibility is your ability to be believed as trustworthy in regards to the subject. Whether you're talking to a group of teenagers or professional adults, your credibility doesn't change. Your clarity also should not change based on the audience because you want to be clear in your message at all times. Also, your purpose should be the same no matter the audience. The only thing that would change is your tone. The way you approach a crowd of teenagers would vary greatly from the way you'd approach a room of professionals.
I think the right one is A
