Given the fact "shivering is when an animal creates heat by shaking to keep the body warm", what is the answer to the question or completion "A dog outside could be shuddering uncontrollably. Which of these could be related?"

Choose your answer from:
(1). they were scared by their own shadow.
(2). they ate too much food.
(3). white precipitation is falling and it's windy.
(4). they are very tired.
(3).