According to one study, students’ academic performance is not the only decisive factor of their stress responses.[A] Given all that’s riding on having a successful ninth grade experience, it pays to explore what can be done to meet the academic, social and emotional challenges of the transition to high school. So far our studies have yielded one main insight: Students’ beliefs about change—their beliefs about whether people are stuck one way forever, or whether people can change their personalities and abilities—are related to their ability to cope, succeed academically and maintain good mental health. Past research has called these beliefs “mindsets (思维模式),” with a “fixed mindset” referring to the belief that people cannot change and a “growth mindset” referring to the belief that people can change.[B] In one recent study, we examined 360 adolescents’ beliefs about the nature of “smartness”—that is, their fixed mindsets about intelligence. We then assessed biological stress responses for students whose grades were dropping by examining their stress hormones (荷尔蒙). Students who believed that intelligence is fixed—that you are stuck being “not smart” if you struggle in school—showed higher levels of stress hormones when their grades were declining at the beginning of the ninth grade. If students believed that intelligence could improve—that is to say, when they held more of a growth mindset of intelligence—they showed lower levels of stress hormones when their grades were declining. This was an exciting result because it showed that the body’s stress responses are not determined solely by one’s grades. Instead, declining grades only predicted worse stress hormones among students who believed that worsening grades were a permanent and hopeless state of affairs.[C] We also investigated the social side of the high school transition. In this study, instead of teaching students that their smartness can change, we taught them that their social standing—that is, whether they are bullied or excluded or left out—can change over time. We then looked at high school students’ stress responses to daily social difficulties. That is, we taught them a growth mindset about their social lives. In this study, students came into the laboratory and were asked to give a public speech in front of upper-year students. The topic of the speech was what makes one popular in high school. Following this, students had to complete a difficult mental math task in front of the same upper-year students.[D] Experiment results showed that students who were not taught that people can change showed poor stress responses. When these students gave the speech, their blood vessels contracted and their hearts pumped less blood through the body—both responses that the body shows when it is preparing for damage or defeat after a physical threat. Then they gave worse speeches and made more mistakes in math. But when students were taught that people can change, they had better responses to stress, in part because they felt like they had the resources to deal with the demanding situation. Students who got the growth mindset intervention（干预）showed less-contracted blood vessels and their hearts pumped more blood—both of which contributed to more oxygen getting to the brain, and, ultimately better performance on the speech and mental math tasks.[E] These findings lead to several possibilities that we are investigating further. First, we are working to replicate (复制) these findings in more diverse school communities. We want to know in which types of schools and for which kinds of students these growth mindset ideas help young people adapt to the challenges of high school. We also hope to learn how teachers, parents or school counselors can help students keep their ongoing academic or social difficulties in perspective. We wonder what would happen if schools helped to make beliefs about the potential for change and improvement a larger feature of the overall school culture, especially for students starting the ninth grade.请选择和题干内容相一致的段落。A、[A]B、[B]C、[C]D、[D]E、[E]