The main idea of the book is that three animals risk their lives to return home.
The main idea of a literary text is the central idea or point that the text makes. This can be identified through the author's use of certain words, or what the text is mainly about.
The main point or idea that the short context seems to make is that these three animals risk their lives to get back home safely. Thus, the correct answer is the fourth option.
Learn more about main idea here:
https://brainly.com/question/10255213