单项选择题

Questions 21 to 22 are based on the following news. At the end of the news item, you will be given 10 seconds to answer the questions. Now listen to the news. Which of the following statements is true of FBI, according to this news

A.It was alerted about the Sept. 11, 2001 terrorist attacks as early as 2000.
B.It captured some terrorists secretly in 2000.
C.It arrested Anthony Shaffer before Sept. 11, 2001.
D.It reported the threat on the Sept. 11,2001 terrorist attacks to the White House.