Which of the following scenarios BEST describes an implementation of non-repudiation? 

Answer options:

A. A user logs into a domain workstation and access network file shares for another department
B. A user remotely logs into the mail server with another user`s credentials
C. A user sends a digitally signed email to the entire finance department about an upcoming meeting
D. A user access the workstation registry to make unauthorized changes to enable functionality within an application

C