Well, we can answer this fairly easily, without having to go through every single cell, and look up its neighborhood in the table. We can look at this very last cell here, and we see that its neighborhood is white white, and then we wrap around to get white. Three whites go to a white, so the middle, this cell here, will be white. So that eliminates B and C. It's either A or D. OK. And then let's look at this cell here well, black white black, we see goes to black. But in choice A, it's white in choice D, it's black. So by elimination, you can know that the correct answer is D. And you can go through if you want, to verify and make sure that it all works. You can go through each one. But this indeed is the answer.