>>10974598B is a brainlet answer. It's an IQ test so the answer should of course be counterintuitive. So here's why it's c. First off it offers a nice contrast to all the black. I mean without a little white in there the space would look a little cramped, you want light colors especially around the corners to create the impression of space. Of course f or d might seem like viable alternatives but the sameness with the other quadrillaterals would kind of defeat the purpose of adding the contrasting white. But C is also kind of just a nice change of pace after so many 4 sided figures, why not have a circle there to mix things up a bit? Surely this most aesthetic of choices can be called equally, if not more adequately well-reasoned alongside the obvious red herring, B
