In this line from "Frankenstein", by Mary Shelley, based on the context, the option that best explains the word apathy is opposite of enthusiasm.
In Chapter 2, Victor is relating how close to his family he is. He writes that his sister is less than one year old younger than him and that they are all very close. They all go to the bath in Thonon and because of bad weather they have to spend some time indoors. He finds a book wrote by Cornelius Agrippa and although he opens it with apathy (no enthusiasm) when he starts reading his mood changes into an enthusiastic mood.