In the recent period, there have been many rumors about an earthquake. One evening, Xiaofang asked the uncle in the courtyard: "Oh, they all said that the day is going to be an earthquake. " He said, "According to my observation, tomorrow is not necessarily an earthquake "Xiaofang said," Then you mean that there will definitely not be an earthquake tomorrow. "He said wrong. Xiaofang was confused. Which of the following statements is closest to what you mean? ? ['May not be earthquake tomorrow.', 'Possible earthquake tomorrow.', 'Tomorrow cannot be without earthquake.', 'No earthquake tomorrow.']