You didn't underline anything, so we cannot know for sure what the correct answer is. However, I'll just write down the entire infinitive phrases in these sentences, and you can see the answer based on that:
1. to see a great play
2. to cheer good plays
3. to practice until you know all the plays
Gothic elements are presented in the book when the author reveals that Dr Jekyll and Mr Hyde are the same people just doubling. This is shown by revealing dark themes of the supernatural when Jekyll transforms into Hyde by the fear of committing horrific crimes as himself and feeling the guilt. Some gothic characteristics this gothic book includes is death and madness which is shown in one of the themes good versus evil. Jekyll and Hyde are metaphorical to the idea of good and evil exist in everyone and the struggle of the two sides raging within Jekyll which result in his death.
A) Family is the most important thing in life