Please choose the correct answer to the question: A mouse is being hunted by a Great Horned Owl. The owl watches the mouse carefully, and the mouse is unaware that it is being hunted. The mouse is unable to tell where the owl is, because

Answer1: the owl is invisible Answer2: the mouse is oblivious Answer3: the mouse is blind Answer4: the owl matches its background

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