In a recent film set in seventeenth-centur

题目：

In a recent film set in seventeenth-century Europe, the hero is seen doing the crawl, a swimming stroke not known in Europe before the 1920’s. However; since moviegoers obviously are not experts in the history of swimming strokes, for most of the film’s audience this blunder clearly cannot have interfered with whatever sense of historical authenticity the film otherwise achieved.
Which of the following, if true, most seriously weakens the argument given

A．The film was widely praised for being historically plausible, even though it portrayed many events that were not historically attested.

B．The scene that shows the film’s hero doing the crawl is a rescue scene pivotal to the film’s action, and parts of it are even shown a second time, in a flashback.

C．Makers of historical films, even of those set as recently as the nineteenth century, routinely strike compromises between historical authenticity and the need to keep their material accessible to a modern audience, as in the actors’ speech patterns.

D．The crawl that European swimmers used in the 1920’s was much less efficient and more awkward-looking than the crawl that is currently taught.

E．(E) A slightly earlier film featuring an eighteenth century sea battle in Europe was ridiculed in numerous popular reviews for the historical lapse of showing a sailor doing the crawl in swimming to safety.