Which file, when using Sendmail or a similar MTA system, will allow a user to redirect all their mail to another address and is configurable by the user themselves?

A.
/etc/alias

B.
/etc/mail/forwarders

C.
~/.alias

D.
~/.forward

Explanation/Reference:
From wikipedia:

~/.forward files
sendmail, the reference SMTP implementation in the early 1980s, provided for ~/.forward files, which can store the target email-addresses for given users. One can configure some email-program filters to automatically perform forwarding or replying actions immediately after receiving. Forward files can also contain shell scripts, which have become a source of many security problems.

Email predates the formalization of client–server architectures in the 1990s.[11] Therefore, the distinction between client and server seems necessarily forced. The original distinction contrasted daemons and user-controlled programs which run on the same machine. The sendmail daemon used to run with root privileges so it could impersonate any user whose mail it had to manage. On the other hand, users can access their own individual mail-files and configuration files, including ~/.forward. Client programs may assist in editing the server configuration-files of a given user, thereby causing some confusion as to what role each program plays.