The characters don't fit in with their surroundings.
The reason why "good vs. evil" is a universal theme is because there are always two forces at work one for good and one for evil and for every good/evil thing there is an evil/good thing that will go up against each other until the end of time or at least until one of them is defeated, but then another good/evil thing will appear to take it place.
Example 1:
Your in high school and there is a bully and you try to stop the bully from hurting others. This makes you the good force and the bully the evil force (he/she doesn't have to be "evil" per-say just bad or mean will do).
That’s fair, hope it works out
The correct answer should be<span> Evil can never truly hide itself.
Hyde is finally revealed as to who he is and what is he doing there. The last two possible answers are not themes but rather plot elements, while the second is not found in this paragraph.</span>