What Is the Process Used by a Fax (Facsimile) Machine

What is the process used by a fax (facsimile) machine to send documents from one location to another ?

A) The fax machine takes a photograph of the document which is transmitted electronically.
B) The fax machine scans the document like a computer scanner so that it can be transmitted.
C) The fax machine encodes the images on the document into signals to be sent over the telephone.
D) The fax machine encodes the images on the document into electronic signals to be sent over the Internet.