B. Because you don't want to have a sentence that isn't complete in an essay
First, the speaker is in his chamber late at night reading
his old books.
Second, the
speaker starts feeling drowsy when he hears a tapping at the window.
Third, the
speaker gets even more frightened when the curtains rustle.
Fourth, the
speaker hears a noise at the window, and a raven flies into the room.
<span>Lastly, The
speaker is surprised to find no one when he opens his door.</span>
