单选题：When a file is opened by a user process for the first time, whic

When a file is opened by a user process for the first time, which operation should the operating system do?@[A](1)
A. To copy the file control block into memory
B. To read the file content into memory
C. To modify the read/write right in file control block
D. To return the data buffer pointer of the file to user process




A.To copy the file control block into memory
B.To read the file content into memory
C.To modify the read/write right in file control block
D.To return the data buffer pointer of the file to user process


答案：A