And actually, if I had looked at the choices ahead of time, I might have even been able to save even more time by just saying, well, look, actually, if you just try to compute the first term, when n is equal to one, it would be k over two. Well, only this one is starting with a k over two. This one has no k's here, which is sketchy. They're trying to look at the error where you try to replace the k with the number as well, not just the n. So that's what they're trying to do here. Here, they're trying to, let's see, well, this isn't as obvious what they're even trying to do, right over here where they put the k in the denominator. And here, if you swapped the n and the k's, then you would have gotten this thing right over here. So we definitely feel good about choice A.