It failed because either the change did not work well in many business settings, or it was inefficient (due to the inefficiency of the conveyer-belt system). A more accurate reason is that the circuits couldn't handle the traffic during peak hour. The customer's orders were regularly mixed up. The conveyer-belt system was not fast enough or efficient enough to handle it.
I don't know the context, but D, "The Simile is meant to evoke horror in the reader; <span>the autumn leaves are red--but not just any red, the red blood of a murdered child." seems to be the correct answer.</span>
