Given the ls command output that is shown below, what command will permit only the user owner and members of the "staff" group to read or modify the testpcap file?
$ ls -l test
-rw-r–r– 1 jdoe staff 57 Nov 3 10:13 testpcap
A. chmod 660 testpcap
B. chmod 550 testpcap
C. chmod o+rw testpcap
D. chmod staff+rw testpcap
