Which will run user-specified code before an interface is brought up?

A.
Write a custom script and install it in /etc/if-post-up.d/

B.
Write a custom script and install it in /etc/if-pre-up.d/

C.
Write a custom script and install it in /etc/if-up.d/

D.
Write a custom script and install it in /etc/if-up/