Bram Stoker’s 1897 novel <i>Dracula</i> was not the first work of literature to feature vampires, but it was the first to portray them as being able to turn into bats. Since none of the European vampire myths that predated <i>Dracula</i> mentioned this ability, the ability to turn into a bat is not essential to the vampire myth.

Question: Which one of the following is an assumption on which the argument depends?
Options:
A. At least one of the European vampire myths that predated Stoker’s book did not portray vampires as strictly nocturnal.
B. Vampire myths in Central and South America, where real vampire bats are found, portray vampires as able to turn into bats.
C. Vampire myths did not exist outside Europe before the publication of Stoker’s Dracula.
D. At least one of the European vampire myths that predated Stoker’s book did not portray vampires as able to turn into bats.
E. At the time he wrote Dracula, Stoker was familiar with earlier European vampire myths.
Answer: "D"