A technician is installing an MFD.

RJ11 is the standard interface for telephone lines and is required for faxing functionality. Most multifunction devices (MFDs) that support faxing need to be connected to a phone line via an RJ11 connection to transmit and receive faxes.

B. RJ45 is used for Ethernet connections, not for faxing.

C. USB is used for connecting peripherals but does not support faxing.

D. Bluetooth is a wireless technology, not typically used for fax functionality.

References:

CompTIA A+ Certification Study Guide

Official CompTIA IT Fundamentals (ITF+) Study Materials