im reading the book now, so give me a few minutes and ill answer the best i can!
The correct answer is B.
When Pi tells the second, more brutal account of what happened, the reader understands how important storytelling is to Pi and how changing the events into a story helped him survive. Furthermore, we can see how Pi had a will to live even in the face of certain death.
B. Bone denesity because as we age our bones become brittle and can break easily hence why older people often break their wrist or hips when falling. And being fit can help.