On Tuesday August 11th, 1911, a young artist, Louis Beraud, arrived at the Louvre in Paris

to complete a painting of the Salon Carre. This was the room where the world's most famous painting, the Mona Lisa by Leonardo da Vinci, was on display. To his surprise there was an empty space where the painting should have been. At 11 o'clock the museurn authorities realized that the painting had been stolen. The next day headlines all over the world announced the theft.

Actually the Leonardo had been gone for more than twenty-four hours before anyone noticed it was missing. The museum was always closed on Mondays for maintenance. Just before closing time on Sunday three men had entered the museum, where they had hidden themselves in a storeroom. The actual theft was quick and simple. Early the next morning Perrugia removed the painting from the wall while the others kept watch. Then they went out a hack exit.

Nothing was seen or heard of the painting for two years when Perrugia tried to sell it to a dealer for half a million lire. Perrugia was arrested on December 13th Perrugia claimed he had stolen it as an act of patriot-ism, because, he said, the painting had been looted from the Italian nation by Napoleon. Perrugia was imprisoned for 7 months. It seemed that the crime of the century had been solved.

But had it？ Perrugia was keen to claim all responsibility for the theft, and it was twenty years before the whole story came out. In fact Perrugia bad been working for two master criminals, Valfierno and Chaudron, who went unpunished for their crime. They would offer to steal a famous painting from a gallery for a crooked dealer or an unscrupulous private collector. They would then make a copy of the picture and, with the help of bribed gallery attendants, tape the copy to the back of the original painting. The dealer would then be taken to the gallery and would be invited to make a secret mark on the back of the painting. Of course the dealer would actually be marking the copy. Valfierno would later produce forged newspaper cuttings announcing the theft of the original, and then produce the copy, complete with secret marking. If the dealer were to see the painting still in the gallery, he would be persuaded that it was a copy, and that he possessed the genuine one.

Chaudron then painted not one, but six copies of the Mona Lisa, using 400-year-old wood panels from antique Italian furniture The forgeries were carefully aged, so that the varnish was cracked and dirty. Valfierno commissioned Perrugia to steal the original, and told him to hide it until Valfierno contacted him Perrugia waited in vain in a tiny room in Paris with the painting, but heard nothing from his partners in crime. They had gone to New York, where the six copies were already in store. They had sent them there before the original was stolen. At that time it was quite common for artists to copy old masters, which would be sold quite honestly as imitations, so there had been no problems with US Customs. Valfierno went on to sell all six copies for $ 300 000 each. Valfierno told the story to a journalist in 1914, on condition that it would not be published until his death.

Does the story end there？ Collectors have claimed that Perrugia returned a copy. It is also possible that Leonardo may have painted several versions of the Mona Lisa, or they might be copies made by Leonardo's pupils. There has been a lot of controversy and argument about the 450-year-old painting, but after all, maybe that's what She's smiling about.

The painting was probably stolen ______.

A．on the morning of August 11th, 1911

B．on the afternoon of August 11th, 1911

C．on August 10th,1911

D．on August 9th, 1911