On Saturday August 12, 2000, during Northern Fleet training exercises in the Barents Sea, the Russian nuclear submarine Kursk sank in about 100 meters of water with some 118 sailors aboard. It’s known later that several officers were also aboard, observing the training exercises. The Kursk is lying on the ocean floor in the Barents Sea. The Russian Navy said that it was listing 30 degrees to port. Other sources reported it Was listing as much as 60 degrees. According to a Russian newspaper, when the submarine Kursk failed to make contact with the naval command at the right time later that day, Northern Fleet Commander Admiral Vyachesav Popov ordered rescue ships into the area. It took hours to find the submarine, as it didn’t launch a marking buoy before sinking.
Russian Navy Chief insisted that the submarine Kursk had been involved in a major collision, but a great deal of information shows that this is not true. Up till now, it’s believed that an explosion in the torpedo compartment in the nose of the Kursk was the likely cause. Now Russian government officially asked Norway for help in recovering of sailors’ bodies first of all, and Norway has agreed to offer all help. But Russian insisted that only Russians work inside the submarine Kursk and that the work last for about 10～18 working days. It is expected to recover only 25～35 bodies from the Kursk.
It was not until October 25, when a team of Russian divers entered the submarine Kursk, some 350 feet below the surface, that truth became clear. On November 7, in the morning, owing to the icy and the cold weather, a special rescue meeting held on Murmansk decided to stop the whole bodies recovering operation.
From the text we can infer that（）led to the sinking of the submarine Kursk.
A. a small fighting with another foreign submarine
B. an explosion inside the submarine Kursk
C. a great collision inside the submarine Kursk
D. an attack from another foreign submarine