How must Samba be configured such that it can check CIFS passwords against those found in /etc/passwd and /etc/shadow?

How must Samba be configured such that it can check CIFS passwords against those found in /etc/passwd and /etc/shadow?
A . Set the parameters “encrypt passwords = yes” and “password file = /etc/passwd”
B . Set the parameters “encrypt passwords = yes”, “password file = /etc/passwd” and “password algorithm = crypt”
C . Delete the smbpasswd file and create a symbolic link to the passwd and shadow file
D . It is not possible for Samba to use /etc/passwd and /etc/shadow directly
E . Run smbpasswd to convert /etc/passwd and /etc/shadow to a Samba password file

Answer: D