The Solaris papers described a solution where the user-level threading library installs special signal handlers for all signals. Choose all correct endings to the following section:
The signals are handled...:
A. ... by the user-level thread where the signal is originally delivered
B. ... by a user-level thread that has the signal enabled and that can be scheduled on the same CPU.
C. ... by a kernel-level thread that has the signal enabled
D. ... by the user-level threading library handlers