The explanation given was this: "If 1 is in the solution, then the third turn tells us that (3, 6, 5) cannot be in the solution. The only 3 numbers left are (2, 4, 7) and looking over the first two turns, they would be compatible. So the four numbers (1, 2, 4, 7) could be in the solution together."
The third turn showed that (3 1 6 5) had just one correct digit, not in the right location.
As two players pointed out to me, the third turn shows that (2 4 7) have to be in the solution, regardless of the status of 1. We need four digits, the third turn tells us that at most one of (1 3 6 5) are in the solution, so we need all of the other three digits (2 4 7).
Thus, 2, 4 and 7 must be in the solution - but that fact has nothing to do with whether or not 1 is in the solution.
In other words, even if 1 is not in the solution, 2, 4 and 7 must still be in the solution.
So what's a poor quiz administrator to do about this? I was at first tempted to do what I usually do: give everyone credit for a correct answer to this choice, and change the text to get rid of this "problem."
But then I thought: wait a minute, the whole point of this puzzler is to test our facility with logical thinking. Clearly, I have demonstrated that I am not as good at this sort of thing as I thought (and by the way, 62% of all players selected this choice as correct).
So it seems to me that what I should do is (a) change this choice to be incorrect; (b) recalculate the scores of all players; (c) change the difficulty level of this quiz to Advanced.
What do you think, dear players?