Bram Stoker's 1897 novel Dracula portrayed vampires, the “undead” who roam at night to suck the blood of living people, as able to turn into bats. As a result of the pervasive influence of this novel, many people now assume that a vampire's being able to turn into a bat is an essential part of vampire myths. However, this assumption is false, for vampire myths existed in Europe long before Stoker's book.
Which one of the following is an assumption on which the argument depends?The argument says bat transformation is not essential to vampire myths because vampire myths existed before Dracula.
The missing assumption is that at least some earlier vampire myths did not include
turning into bats. If all earlier vampire myths also had that feature, then the argument would fail.
(A) At least one of the European vampire myths that predated Stoker's book did not portray vampires as strictly nocturnal.
This is not required. The argument is about whether vampires turning into bats is essential, not whether vampires are strictly nocturnal.
(B) Vampire myths in Central and South America, where real vampire bats are found, portray vampires as able to turn into bats.
This is irrelevant. The argument concerns European vampire myths before Dracula.
(C) Vampire myths did not exist outside Europe before the publication of Stoker's Dracula.
This is not required. The argument does not depend on whether vampire myths existed outside Europe.
(D) At least one of the European vampire myths that predated Stoker's book did not portray vampires as able to turn into bats.
This is correct. To show that bat transformation is not essential to vampire myths, the argument needs at least one pre-Stoker vampire myth that lacks that feature.
(E) At the time he wrote Dracula, Stoker was familiar with earlier European vampire myths.
This is not required. The argument is about whether the bat-transformation feature is essential to vampire myths, not about what Stoker personally knew.
Answer: (D)