A、One of them knew a lot about marine life. B、One of them was raising a shark of his own. C、They took Miss Helen away for a joke

Miss Helen is a 40-centimeter-long gray horn shark. She spends her time in a touch tank at the San Antonio Aquarium, where visitors are permitted to touch sea creatures. On Saturday afternoon, a group of thieves took Helen out of the tank. Then, they put the animal in a wheeled baby carrier and walked out of the aquarium before anyone noticed Miss Helen was missing.
The “great shark heist,” as people are calling it, was captured on surveillance video. On Monday night, police found Miss Helen in a home filled with fish tanks and other ocean wildlife. She has been safely returned to the aquarium and appears to be in good health. Experts at the aquarium will be closely examining Miss Helen’s health and behaviour over the next few days before returning her to the tank. Local police chief Joseph Salvaggio said two men have admitted to taking the shark. Investigators also plan to talk with the woman seen in the video. Salvaggio told the San Antonio television station KSAT that one of the men was very knowledgeable about marine life. He likely went to the aquarium especially to take Miss Helen. The man told police he had had a horn shark of his own, but the animal died. Texas law enforcement officials are speaking with the National Oceanic and Atmospheric Administration to see whether any federal charges can be filed, Salvaggio said.
Questions 12 to 15 are based on the passage you have just heard.
12. How did the thieves take the horn shark away?
13. How many people admitted to being involved in the shark stealing?
14. What did the local police chief say about the thieves?
15. Why did the man take Miss Helen away?