It happened in the late fall of 1939 when, after a Nazi submarine had penetrated the Briti

sh sea defense around the Firth of Forth and damaged a British cruiser, Reston and a colleague contrived to get the news past British censorship. They cabled a series of seemingly harmless sentences to The Times's editors in New York, having first sent a message instructing the editors to regard only the last word of each sentence. Thus they were able to convey enough words to spell out the story. The fact that the news of the submarine attack was printed in New York before it had appeared in the British press sparked a big controversy that led to an investigation by Scotland Yard and British Military Intelligence. But it took the investigators eight weeks to decipher The Times's reporters' code, an embarrassingly slow bit of detective work, and when it was finally solved the incident had given the story very prominent play, later expressed dismay that the reporters had risked so much for so little. And the incident left Reston deeply distressed. It was so out of character for him to have. become involved in such a thing. The tactics were questionable and, though the United States was not yet in the war, Britain was already established as America's close ally and breaking British censorship seemed both an irresponsible and unpatriotic thing to do.

The episode recounted in the passage took place ______.

A．just prior to the outbreak of the Second World War

B．bofore Britain entered the Second World War

C．before the United States entered the Second World War

D．while the United States was in the Second World War