请阅读Passage l。完成第小题。

Passage 1

Unless you spend much time sitting in a college classroom or browsing through certain areas of the Internet, it's possible that you had not heard of trigger warnings until a few weeks ago, when they made an appearance in the Times. The newspaper explained that the term refers to preemptive alerts, issued by a professor or an institution at the request of students, indicating that material presented in class might be sufficiently graphic to spark symptoms of post-traumatic-stress disorder.

The term seems to have originated in online feminist forums, where trigger warnings have for some years been used to flag discussions of rape or other sexual violence. The Times piece, which was skeptically titled "Warning: The Literary Canon Could Make Students Squirm," suggested that trigger warnings are moving from the online fringes to the classroom, and might be more broadly applied to highlight in advance the distress or offense that a work of literature might cause.

"Huckleberry Finn" would come with a warning for those who have experienced racism; "The Merchant of Venice" would have an anti-Semitism warning attached. The call from students for trigger warnings was spreading on campuses such as Oberlin, where a proposal was drafted that would advise professors to"be aware of racism, classism, sexism, and other issues of privilege and oppression" in devising their syllabi; and Rutgers, where a student argued in the campus newspaper that trigger warnings would contribute to preserving the classroom as a"safe space" for students.

Online discussion of trigger warnings has sometimes been guardedly sympathetic, sometimes critical. Jessica Valenti has noted on The Nation's website that potential triggers for trauma are so manifold as to be beyond the possibility of cataloguing : "There is no trigger warning for living your life." Some have suggested that a professor's ability to teach would be compromised should it beco

• A.It may highlight the purpose of literature teaching
• B.It may expose students to the dark side of the world
• C.It may deprive students of their intellectual growth
• D.It may cause students to experience a post-traumatic-stress disorder