In this passage, scrooge's door knocker turns into the face of his friend marley. which of the following best describes this event?
a. flashback
b. setting
c. tone
d. supernatural

I believe the answer to be D. Supernatural.

Explanation:

A flashback is a transition to an earlier time in the story, interrupting the chronological order of events. It does happen in "A Christmas Carol", the story to which this question refers, but it does not concern the face of the door knocker.

Setting is the time, place, and social/historical context in which a story takes place.

The tone is an attitude the author takes toward his or her subject, characters, and readers. It conveys emotions or sensations - happy, dreamy, melancholy etc.

We are left with supernatural. Supernatural is, by definition, an event that cannot be explained by nature or science and is assumed to originate from otherworldly sources. In literature, the most common supernatural elements are probably witches and ghosts. That is the case in "A Christmas Carol". What Scrooge sees is a ghost whose face turns into the face of his friend Marley. Throughout the story, Scrooge is visited by ghosts who show him his past, present, and future. Those visions end up softening his heart.

it was surely an odd creature that one made up by reading the historians first and the poets afterwards a worm winged like an eagle; the spirit of life and elegance and charm,   in a kitchen chopping up suet. but these creatures, monst'r however entertaining to the imagination, hast no existence in fact. what one might doth to bringeth h'r to life wast to bethink poetically and prosaically at one and the same moment,   thus keeping in toucheth with fact—that the lady is mrs martin, ag'd thirty-six, did dress in blue, wearing a black coxcomb and brown shoeth; but not losing sight of fiction eith'r—that the lady is a vessel in which all s'rts of spirits and f'rces art coursing and flashing p'rpetually. the moment, howev'r, yond one tries this method with the elizabethan mistress, one brancheth of illumination fails; one is did hold up by the scarcity of facts.   one knoweth nothing detailed, nothing p'rfectly true and substantial about h'r.   hist'ry scarcely mentions h'r.   and i did turn to professeth'r trevelyan again to seeth what hist'ry meanteth to that gent.   i hath found by looking at his chapt'r headings yond t meanteth.