The following is a true story. It happened in the northern end of Queensland, Australia, where all kinds of animals live in the forest. Lisa, a 33-year-old woman, went to prepare lunch in the kitchen, leaving Barney, her three-year-old son, playing by himself in the back garden. Suddenly, a sharp cry of Barney came into the mother's ears, and Lisa rushed into the backyard in a hurry and found a big snake entwining the little child with its terrible body and trying to eat the boy as its delicious dish! It was a boa ! Lisa was terrified and quite angry. She made up her mind to save her son from the snake's mouth. It was fearless mother love that made Lisa forget what she faced. She took up an old hoe from the ground and beat the boa with all her might. One...two... With the hoe, Lisa beat the snake repeatedly, but useless. The little boy's voice and breath were getting weaker and weaker. Lisa's heart was broken and she got nearly mad. Suddenly Lisa put away the hoe and threw herself to the boa, opening her mouth and bit into the boa's back as if trying to eat a rare steak . Lisa was really mad! Blood was spurting  out of the boa's body and covered most of Lisa's body. The boa was so badly wounded that it let go of  Barney and moved back into the forest hurriedly. It had never known how a man had such terrible sharp teeth! On halfway home, the boa died. It was fearless mother love that saved the little boy. Lisa bit the snake because    _   .
she was mad she thought her teeth were much sharper than the boa her son was entwined by the boa she hadn't got any other way to fight with the snake
Question: The following is a true story. It happened in the northern end of Queensland, Australia, where all kinds of animals live in the forest. Lisa, a 33-year-old woman, went to prepare lunch in the kitchen, leaving Barney, her three-year-old son, playing by himself in the back garden. Suddenly, a sharp cry of Barney came into the mother's ears, and Lisa rushed into the backyard in a hurry and found a big snake entwining the little child with its terrible body and trying to eat the boy as its delicious dish! It was a boa ! Lisa was terrified and quite angry. She made up her mind to save her son from the snake's mouth. It was fearless mother love that made Lisa forget what she faced. She took up an old hoe from the ground and beat the boa with all her might. One...two... With the hoe, Lisa beat the snake repeatedly, but useless. The little boy's voice and breath were getting weaker and weaker. Lisa's heart was broken and she got nearly mad. Suddenly Lisa put away the hoe and threw herself to the boa, opening her mouth and bit into the boa's back as if trying to eat a rare steak . Lisa was really mad! Blood was spurting  out of the boa's body and covered most of Lisa's body. The boa was so badly wounded that it let go of  Barney and moved back into the forest hurriedly. It had never known how a man had such terrible sharp teeth! On halfway home, the boa died. It was fearless mother love that saved the little boy. Lisa bit the snake because    _   .
A. she was mad
B. she thought her teeth were much sharper than the boa
C. her son was entwined by the boa
D. she hadn't got any other way to fight with the snake
Answer: