Which command will assign the value true to key /my/var in the gconf database?

A.
gconf -set "/my/var" -type boolean "true"

B.
gconftool-2 -set "/my/var" -type bool "true"

C.
gconftool-2 -set /my/var true

D.
gconf-edit -set "my/var" -boolean "true"

E.
gconf-edit -set /my/var true