[amp_mcq option1=”2F8H” option2=”3F8H” option3=”3E8H” option4=”2E8H E. None of the above” correct=”option2″]
The correct answer is: B. 3F8H
COM4 uses I/O port 3F8H. This is a standard I/O port for serial communication. It is used to send and receive data between the computer and a serial device, such as a modem or a printer.
The other options are incorrect. Option A, 2F8H, is the I/O port for COM2. Option C, 3E8H, is the I/O port for COM3. Option D, 2E8H, is not a valid I/O port.
I hope this helps!