Context: Can I say , Yesterday was a rainy day . John fell down and hurt his knee . ( a ) John tried to walk but failed . Luckily , he saw two scouts was on the way to him .
Question: Why may have John hurt his knee ?
Option 0: The scouts pushed him .
Option 1: He slipped on a wet surface .
Option 2: He was pushed by the scouts .
Option 3: He was fooling around .
Answer: 1