Which command will delete the environment variable FOOBAR?
A.
unset FOOBAR
B.
del $FOOBAR
C.
export FOOBAR
D.
export FOOBAR=
Explanation:
From http://www.slackbook.org/html/shell-bash.html:
$ unset VARIABLE
unset will remove any variables that you give it, wiping out both the variable and its value; bash will forget that variable ever existed.