Reading the CCNA Study Guide, 4th Edition I came across the following. It is the answer to a multiple choice review question. (edited and emphasis added)
[...], so option A is wrong. [...], option B is wrong. [...], so option C is correct. [...], so option E is correct. [...], so option F is incorrect. This leaves option D, which must be correct, but doesn’t make much sense.
Which is exactly what I was thinking when I saw option D.
Just for the record, option D said "If your design is hierarchical, then you don't need multiple [OSPF] areas."
They rephrased it slightly for the 5th edition:
This leaves option D, which must be correct; it doesn't make much sense, but it is the best answer.
So just remember, when you're studying hard and you think something doesn't make sense, maybe it's not supposed to!