阅读下列短文，从每题所给的几个选项中，选出最佳选项。
Harry and Annie lived a mile from town, but they walked there to school every day. It was a happy walk around the pond（水塘） on their way to school. In winter, when the ice was thick enough, they went across the pond. But their mother did not like them to do this. She said, "If there's no one with you, you mustn't walk across the pond. "
"Don't go across the pond today, children," she said, as she kissed them goodbye one morning. "It is beginning to thaw. "
"All right, mother," said Harry, not very happy, for he liked running and sliding（滑行） on the ice very much.
When they came to the pond, the ice looked hard and safe.
"There," Harry said to his sister, "let's slide over it. "
"But you promised mother," said Annie.
"No, I didn't, I only said ‘All right', and it is all right. "
"I didn't say anything, so I can do what I like," said Annie.
So they got on the ice and started to go across the pond.
They had not gone far before the ice got broken, and suddenly they fell into the water.
Luckily, a man who was at work near the pond heard the children's cries. He rushed into the water and saved them successfully. Both of them were nearly drowned （淹死） before the man reached them.
They went home almost frozen（冻僵的） and learned a lesson they would remember for a lifetime.