A、They tied the pirates with strong ropes. B、They killed all the pirates. C、They killed 24 harmful snakes. D、They killed themsel

Something strange happens every year from August 6 to 15 on the West Faronia Island in Greece: thousands of snakes crawl out of the cliffs and caves to gather under the picture of the Virgin in local church. Several days later, these snakes leave the picture one by one.
    This has lasted for several hundreds of years. Stranger still, these snakes had cross-shaped patterns on their heads. They crawl here and there under the picture of the Virgin, never hurting anyone. They even let people touch them.
    There is a beautiful legend to these snakes. Several hundred years ago, there lived 24 nuns in the Virgin convent on Faronia Island. One day. a group of pirates came invading the land. They tied the nuns with ropes and did insult to them. Unable to tolerate the humiliation, the nuns all committed suicide. They turned into 24 snakes, "Sacred snakes".
    The yearly visit of these snakes to the Virgin happens to be associated with the local religious festivals held during these days on this island. That is why these snakes are related to religion. But why these snakes come out on these days instead of any other days, and why they gather under the picture of the Virgin, has remained a mystery.