Which is NOT mentioned as a cause of American stud

单项选择题

In her 26 years of teaching English, Shannon McGuire has seen countless misplaced commas, misspelled words and sentence fragments.
But the instructor at US"s Louisiana State University in Baton Rouge said her job is getting harder every day.
"I kid you not, the number of errors that I"ve seen in the past few years have multiplied five times," she said.
Experts say email and instant messaging are at least partly to blame for an increasing indifference toward the rules of grammar, spelling and sentence structure.
They say the problem is most noticeable in college students and recently graduates.
"They used to at least feel guilty (about mistakes)," said Naomi Baron, professor of linguistics at American University in Washington, D. C. "They didn"t necessarily write a little better, but at least they felt guilty."
Ironically, Baron"s latest book, "Alphabet to Email: How Written English Evolved and Where It"s Heading," became a victim of sloppy proofreading. The book"s title is capitalized differently on the cover, spine and title page. "People used to lose their jobs over this," she said. "And now they just say "whatever"."
"Whatever" describes Jeanette Henderson"s attitude toward writing. The sophomore at the University of Louisiana at Monroe admits that her reliance on spellcheck has hurt her grades in English class. "Computer has spoiled us," she said.
But the family and consumer sciences major believes her future bosses won"t mind the mistakes as much as her professor does. "They"re not going to check semicolons, commas and stuff like that," Henderson said.
LSU"s McGuire said she teaches her students to use distinct writing styles that fit their purpose.
She emphasizes that there"s the informal language of an email to a friend, but there"s also the well thought out and structured academic or professional style of writing.
It"s not just email and instant messaging that are contributing to slack writing habits.
Society as a whole is becoming more informal. Casual wear at work used to be reserved for Friday, for example, but is now commonplace at most offices. There"s also a greater emphasis on youth culture, and youth tend to use instant messaging more than adults do.
English language has been neglected at different points in history but always rebounds. During Shakespearen times, for example, spelling wasn"t considered important, and early publishers rarely proofread.
There will likely be a social force that recognizes the need for clear writing and swings the pendulum back.

Which is NOT mentioned as a cause of American students" casual writing

A．Emailing
B．Slack teaching
C．Youth culture
D．Instant messaging