The correct answer is None of the above.Serial ports are used to connect various devices serially.An asynchronous port on the computer is used to connect a serial device to the computer and capable of transmitting one bit at a time.Serial ports are usually identified on IBM-compatible computers as COM (communications) ports. The serial port is found on the back of the computer and is part of the motherboard.Serial port, you can notice the DB9 serial port connection is easy to identify. The connection is in the shape of the letter D, is a male connector, and has 9 pins. A serial port can only transmit one bit of data at a time, whereas a parallel port can transmit many bits at once.Important PointsAdditional InformationTypes of serial ports are:DB9: Is a 9-pin connection.DB25: This is a 25-pin connection.