How should read， write and execute permissions for ‘group’ and ‘other’ be granted to all files and directories within the /app filesystem？（）

A.‘tty -l’
B.‘stty -a’
C.‘lstty -a’
D.‘terminfo -l’

A.chshell -ksh93 webserver
B.chsh webserver /usr/bin/ksh93
C.chuser -a shell=/usr/bin/ksh93 webserver
D.setuid -a SHELL=/usr/bin/ksh93 -u webserver

A.PMT
B.PS1
C.PRT
D.PT1