An administrator tries to change the checksum_offload setting on ent0， but the chdev command responds that the adapter is busy.  What can be done to resolve this（）？  

• A、Use chdev with -P flag and run cfgmgr.
• B、Use chdev with -R flag and run cfgmgr.
• C、Use chdev with -P flag and reboot the system.
• D、Use chdev with -R flag and reboot the system.