Please choose the correct answer to the question: A new walnut tree sprouted up 200 feet away from the nearest other walnut tree.

Answer1: a walnut was carried to the new spot on a light breeze Answer2: a walnut was picked and carried into a house Answer3: all the walnuts were gathered by a walnut farmer Answer4: a squirrel was forgetful

Answer format: answer1/answer2/answer3/answer4
Answer: answer4