Which of the following directories cannot be placed out of the root filesystem?

Which of the following directories cannot be placed out of the root filesystem?
Each correct answer represents a complete solution. Choose all that apply.

A.
/sbin

B.
/etc

C.
/lib

D.
/var

Explanation:

The following directories cannot be separated from the root filesystem:
/lib
/dev
/etc
/sbin
/bin

Answer option D is incorrect. /var can be separated from the root filesystem. Such filesystems are
known as optional filesystems. Some of the optional filesystems are as follows:
/var
/usr
/opt
/home