50 Which of the following is true about Dr. Nora Volkow?
(A)She thinks that the problem of abusing Ritalin is temporary.
(B)She believes that short-term effects of Ritalin should be studied.
(C)She shows her concern after some researchers argue for the use of Ritalin.
(D)She will write an article to warn people of the danger of Ritalin

Healthy people are increasingly turning to brain-enhancing drugs like Ritalin利他能 for treating narcolepsy猝睡症 to boost改善；提高 their performance in school or at work, researchers said. And while some expressed表露, 陳述 alarm警告, 警報 over the trend趨勢，趨向, others embraced欣然接受；樂意採納 the idea, provided the drugs are proven safe.

“In the United States, stimulant medications are widely abused,” said Dr. Nora Volkow, director經理，管理者，主任 of the National Institute of Drug Abuse. “They are abused for a variety of reasons, including the fact that people want to get high, but there is the realization that they are being increasingly utilized利用（utilize的過去分詞）to improve cognitive感知的；認知 performance,” she said. “This is not something that is going away,” Volkow said, adding that researchers must study the long-term effects these drugs might have in healthy people. Her concern follows a commentary注釋 in the journal Nature that argues for use of the drugs in healthy adults as a legitimate合法的，正當 way of improving brain power, much like education, the Internet, or other helpful tools. “We should welcome new methods of improving our brain function,” Henry Greely of Stanford Law School in California, Barbara Sahakian, a psychiatry professor from the University of Cambridge in Britain and others wrote. They cited舉例 a recent survey that found nearly 7 percent of students in U.S. universities have used prescription藥物, 處方 stimulants, and on some campuses, as many as a quarter of students have used the drugs for non-therapeutic治療 purposes. The researchers called for doctors, educators, regulators, and others to evaluate the risks and develop policies governing the use of cognitive感知-enhancing drugs. Volkow said she and other experts would discuss the issue at the meeting of American College of neuropsychopharmacology神經精神藥理學 in Nashville, Tennessee.