The correct answer is: no article.
The reason is that the third and fourth chapters are not specific chapters, but rather any two chapters that are consecutive. Therefore, we do not need to use an article.
If we were to use an article, it would imply that we are referring to specific chapters. For example, if we said "I read the third and the fourth chapter of the book," it would mean that we are referring to the third and fourth chapters in order, and not just any two consecutive chapters.
In this case, we are not referring to specific chapters, so we do not need to use an article.
