A user requested a USB serial device to be added to a desktop computer. The device has built-in kernel driver support. The administrator tested the device installation and access, but the user cannot access the serial port. Each time the user attempts to access the device, an error log is created that shows the user does not have permission to use the serial port.
Which of the following will add a user to the group that has serial port capabilities?
A. usermod -a -G serialport $USER
B. usermod -a -G modem $USER
C. usermod -a -G dialout $USER
D. usermod -a -G root $USER
