Final answer:
Arthur Holmwood, Lucy Westenra's fiancé, drives the stake through her heart in Bram Stoker's novel Dracula. He does this out of a sense of duty and to find peace in saving her soul. Other characters, such as John Seward, Quincey Morris, and Dr. Van Helsing are involved but do not perform the act.
Step-by-step explanation:
In Bram Stoker's novel Dracula, the character who drives the stake through Lucy Westenra's heart is Arthur Holmwood, her fiancé. The statement that Arthur Holmwood does it as her fiancé and feels responsible for her well-being is true. He indeed feels that it is his duty to save her soul, which makes the statement that it would bring him peace to know he saved her soul also true.
While John Seward is a doctor and would know where to aim the stake, he is not the character who performs the task, therefore the statement is false. Quincey Morris is bold, but this is not the singular reason why he might perform the task, and ultimately, he does not; thus, the statement is false. Lastly, Dr. Van Helsing proposes the idea and orchestrates the events leading up to the act, making the statement that it was his idea true, but he does not personally drive the stake through Lucy's heart, rendering the statement false.