A warrant is an underlying assumption or inference that the writer takes for granted.
Answer: Personafication
Explanation: Personafication means referring to or giving non living things the qualities of human or living things. "Heart of darkness they were discoloured", the heart is part of the human body but in this context it is given the human attribute where "they" pronoun is referred to the heart. Also "backbone is seen running down the middle of his back", backbone is just part of the human body but in this context it it made to run down like it ia literally running down onea back.
sorry but i dont know search it on the internet instead