Please choose the correct answer to the question: A 40 foot wide hole is found in the dessert. It's shaped like a ball had hit it. What could have happened?

Answer1: something from space entered the atmosphere Answer2: a lizard built the hole Answer3: the moon's gravity pulled sand out of the hole Answer4: a dust storm filled it in

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