单选题：In general, user-level threads are _____ to create and manage th

In general, user-level threads are _____ to create and manage than kernel-level threads, because __________. @[C](1)
A. slower, user-level threads have lower execution priority
B. slower, user-level threads may be preempted by kernel
C. faster, no intervention from the kernel is required
D. faster, more kernel-level threads are needed than user-level ones





A.slower, user-level threads have lower execution priority
B.slower, user-level threads may be preempted by kernel
C.faster, no intervention from the kernel is required
D.faster, more kernel-level threads are needed than user-level ones


答案：C