The mouse went to sleep. The mouse ate some food. The mouse started running. The mouse detected an odor.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A mouse's rate of carbon dioxide output increased. Which of the following most likely happened?
Possibilities:
- The mouse went to sleep.
- The mouse ate some food.
- The mouse started running.
- The mouse detected an odor.

The mouse started running.