A.chown -u dave -g staff data.txt

B.chown --user dave --group staff data.txt

C.chown dave:staff data.txt

D.chown dave/staff data.txt

A.chown -u dave -g staff data.txt

B.chown --user dave --group staff data.txt

C.chown dave+staff data.txt

D.

E.chown dave:staff data.txt

A.apt -r /etc/debian_version

B.dpkg -S /etc/debian_version

C.apt-file /etc/debian_version

D.apt-get search /etc/debian_version

E.find /etc/debian_version -dpkg

A.:UPPER:

B.[A-Z]

C.!a-z

D.%C

E.{AZ}