Although the sentence is incomplete, I think that's the correct one. Both Harrison and the ballerina get killed, restoring the world to its previous situations, but their actions don't inspire rebellion and not everybody ends up happy. Harrison's parents don't, although they don't know why they are sad.
Answer:
It is predicate nominative in my opinion
Quote 1: taken from chapter 2:
“And not only did he learn by experience, but instincts long dead became alive again.”
Quote 2: chapter 3 final paragraph
“The dark circle became a dot on the moon-flooded snow as Spitz disappeared from view. Buck stood and looked on, the successful champion, the dominant primordial beast who had made his kill and found it good.”
I need context where is the question