Which of the following is true, when a server uses PAM authentication and both /etc/pam.conf & /etc/pam.d/ exist?

Which of the following is true, when a server uses PAM authentication and both /etc/pam.conf & /etc/pam.d/ exist?

A.
It causes error messages.

B.
/etc /pam.conf will be ignored.

C.
/etc / pam.d/ will be ignored.

D.
Both are used, but /etc/pam.d/ has a higher priority.

E.
Both are used, but /etc/pam.conf has a higher priority.