Which of the following describes the Linux device to which this switch is attached?

A new IO card has been added to the security server to log the opening and closing of the main entrance. A switch is attached, so the interface card returns a 1 when the door is opened and a 0 when the door is closed.

Which of the following describes the Linux device to which this switch is attached?
A . /dev/tty0
B . /dev/port
C . /dev/gpio
D . /dev/sg0

Answer: B