The film stars out as a normal day at a typical American high school. Friends chat in the dining room and boys play football. But there's big surprise when the movie ends with two students going crazy in the school-shooting and killing people. This is Elephant. It stars real school kids. American director Gus Van Sant had no ready-made lines. The student actors made up their own dialogue, with Van Sant asking them to base their characters on their own lives. Although it may not sound very high quality, the film won the Palme d'Or   for Best Film and the award for Best Director at the Cannes film festival. The film is based on the shootings at a high school in the US, where two boys killed 13 people and then themselves in 1999. The title of the movie refers to the old expression about a problem that's as hard to ignore as an elephant in the house. The film takes a close look at a few hours in the lives of the victims and the killers. It shows how high school is a different experience for everyone---fun and friendly, or hard and lonely. In many ways, the two boys, who carry out the shooting, act like ordinary kids. They joke around with one boy's mother as she serves them cakes and play the piano. But there're hints of the anger they feel inside. One of the boys is bullied   at school. The other plays violent video games. But Van Sant isn't blaming their killings on either bullying or violent games. In fact, the film doesn't offer any reason for why school violence happens. "I didn't want to explain anything. It's up to the audience to draw its own conclusions," said the 51-year-old director. The film doesn't tell why school shootings happen  _  .
so as to leave room for the audience to think and judge because life itself is the problem maker because the mental problems of students are hard to explain but there are some hints of the reasons
Question: The film stars out as a normal day at a typical American high school. Friends chat in the dining room and boys play football. But there's big surprise when the movie ends with two students going crazy in the school-shooting and killing people. This is Elephant. It stars real school kids. American director Gus Van Sant had no ready-made lines. The student actors made up their own dialogue, with Van Sant asking them to base their characters on their own lives. Although it may not sound very high quality, the film won the Palme d'Or   for Best Film and the award for Best Director at the Cannes film festival. The film is based on the shootings at a high school in the US, where two boys killed 13 people and then themselves in 1999. The title of the movie refers to the old expression about a problem that's as hard to ignore as an elephant in the house. The film takes a close look at a few hours in the lives of the victims and the killers. It shows how high school is a different experience for everyone---fun and friendly, or hard and lonely. In many ways, the two boys, who carry out the shooting, act like ordinary kids. They joke around with one boy's mother as she serves them cakes and play the piano. But there're hints of the anger they feel inside. One of the boys is bullied   at school. The other plays violent video games. But Van Sant isn't blaming their killings on either bullying or violent games. In fact, the film doesn't offer any reason for why school violence happens. "I didn't want to explain anything. It's up to the audience to draw its own conclusions," said the 51-year-old director. The film doesn't tell why school shootings happen  _  .
A. so as to leave room for the audience to think and judge
B. because life itself is the problem maker
C. because the mental problems of students are hard to explain
D. but there are some hints of the reasons
Answer: