The answer is C - exists in thought or as an idea, but does not have a physical existence.
I would say the word “which” goes in the blank.
Profession wrestler André the Giant suffered from acromegaly, gigantism, which causes the body to produce unusually high amounts of growth hormones.
Hope I helped!
It is somehow related because Sad Perfect is a book about a girl who has an eating disorder, as you know this is not an easy thing to deal with so it would not be uncommon to hate your life. It's not a quote from the book but it can relate.
