Final answer:
In Mary Shelley's Frankenstein, the creature calls Victor a slave and tells him that he is his master, making option A. Master the correct answer for the blank in the sentence.
Step-by-step explanation:
The creature in Mary Shelley's novel Frankenstein has a complex relationship with his creator, Victor Frankenstein. In a pivotal moment, the creature refers to Victor as his creator but also tells him, "you are my creator, but I am your master." Therefore, the correct answer to fill in the blank is A. Master.
The creature's assertion of being Victor's master underscores the power dynamic and the ironic twist in their relationship. Victor, despite being the creator, finds himself subservient to his own creation - a recurring theme that explores the consequences of unchecked ambition and playing god, which are central to the novel's message.