Answer:
The author suggests in this excerpt that it is important for people to be informed about what their bodies need.
Step-by-step explanation:
In the given excerpt from "Healthy Eating," the example of 55-year-old Juanita Ferguson provides one key aspect of careful eating habits. Added to that, she had undergone a kidney transplant which further complicates things.
When the author says "it was the finer points" that Ferguson was missing, it means that those small 'breaks' such as skipping meals on busy days, or consuming the wrong products play a huge role in the maintaining of her health. The suggestion in this excerpt is that it is important for people to be informed and knowledgeable about the needs of their respective bodies.
Thus, the correct answer is the fourth/last option.