Tic-tac-toe is a paper-and-pencil game for two players. 井字棋是一种供两人玩的纸笔游戏。
Rules:规则:
Players choose who uses X as their marker and who uses O. One player starts, then both players take turns marking the spaces in a three-by-three grid with an X or an O. The player who succeeds in placing three of their markers in a horizontal, vertical, or diagonal row is the winner. If no one succeeds and all nine boxes are filled, the game ends in a tie. 玩家选择谁用 X 作为自己的标记，谁用 O。一名玩家先开始，然后两名玩家轮流在三乘三的网格中用 X 或 O 标记空格。成功将三个自己的标记连成一条横线、竖线或对角线的玩家获胜。如果没有人成功且所有九个格子都被填满，游戏以平局结束。
Example:例子:
The following images show the first two moves each player made, and the last move they made in a game.以下图片展示了每位玩家在一场游戏中所下的前两步棋以及他们所下的最后一步棋。
(The moves made on each turn are highlighted.)（每回合所下的棋步均以高亮显示。）
The image on the right is what we call the 'result sheet' of a completed game. Not all sheets that are filled randomly with X or O are valid result sheets according to the rules presented above.右边的图像是我们所说的已完成游戏的“结果表”。并非所有随意填满 X 或 O 的表格都符合上述规则，是有效的结果表。
Question:问题:
Which of the following images is the only valid result sheet of a completed game according to the rules above?根据上述规则，以下哪张图片是唯一有效的已完成游戏的成绩单？
A. 
B. 
C. 
D. 
Explanation 解释
Answer: 答案
:
Explanation: 解释:
This is a valid game because it was won by player O and then stopped.这是一场有效的游戏，因为是玩家 O 赢得了比赛，然后游戏停止了。
Answer is not correct. 答案不正确。
Player X has won the game, but player O has placed more marks than player X, which is not possible.玩家 X 赢得了游戏，但玩家 O 放置的标记比玩家 X 多，这是不可能的。
Since the winning player always places the last mark, they can only have more or an equal number of marks but not less.由于获胜的玩家总是放置最后一个标记，所以他们拥有的标记数量只能更多或相等，而不会更少。
Answer is not correct because there are 5 X-marks but only 3 O-marks. That is not possible. The difference between the numbers can only be 0 or 1.答案不正确，因为有 5 个叉号，但只有 3 个圈号。这是不可能的。数字之间的差值只能是 0 或 1。
Answer is not correct because a winner had not been determined and the fields were not all filled completely.答案不正确，因为当时尚未决出胜者，而且表格也未全部填满。
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