Read the following example. What is the effect of the repetition in these lines? And the silken sad uncertain rustling of each purple curtain
Thrilled me – filled me with fantastic terrors never felt before; So that now, to still the beating of my heart, I stood repeating 'Tis some visitor entreating entrance at my chamber door -Some late visitor entreating entrance at my chamber door; –This it is, and nothing more!

A) It emphasizes the speaker's friendliness.
B) It establishes the poem's tone.
C) It defines an unknown idea.
D)It introduces a new character.