Which is one extraneous detail from this passage? “several key human errors contributed to the spread of the chicago fire of 1871.” “finally, as the blaze raged on, fireman john dorsey attempted to sound a special alarm, but accidentally sounded a general alarm.” “even after the fire, brown was confident in his decision not to correct the mistake.” “when schaffer realized his mistake, brown flat-out refused to strike the correct box.”

If the passage is about the human errors that contributed to the spread of the fire, only details that prevented the firemen from being able to contain the fire should be used. The sentence "Even after the fire, Brown was confident..." shows that Brown was confident in his decision. This sentence does not however directly contribute to the firefighters inability to effectively contain the fire at the time of the fire. This takes place after the fire has done the damage.