It's C. A and B are wrong.
Ya see you do the thing that happens when thing happen to be done
The following are the correct options: THE AUTHOR'S KNOWLEDGE, THE AUTHOR'S OPINION, THE AUTHOR WORLDVIEW AND THE AUTHOR'S EXPERIENCE
All these factors make up the person that the author really is and they are going to affect the way he perceives things. These factors are the determinants of the kind of information and view that will be found in any book that the author writes.
They are both correct because Ralph is saying "half inches", and so if you take 5 and you cut them into half, they add up to 11