In my opinion A, bc if you take out it and say "He had a relaxed attitude about studying for the important exam" is sounds as if being relaxed was actually good.
<em>The answer you are looking for is: </em> <em><u>B.) Jody is immature and innocent. </u></em> <em>Hope that helps!! </em> <em>Have a wonderful day!! </em> <em>If you ever need help feel free to ask me!! </em>