单选题：Which of the following is a probable invocation flow for file-sy

Which of the following is a probable invocation flow for file-system mounting?@[A](1)
A. sys_mount ->do_add_mount -> do_mount
B. do_mount ->sys_mount -> do_add_mount
C. sys_mount -> do_mount -> do_add_mount
D. do_add_mount ->do_mount -> sys_mount




A.sys_mount ->do_add_mount -> do_mount
B.do_mount ->sys_mount -> do_add_mount
C.sys_mount -> do_mount -> do_add_mount
D.do_add_mount ->do_mount -> sys_mount


答案：A