Institution: SONALI BANK LTD Exam: Sonali Bank Ltd - Assistant Programmer - 26.08.2016 ||
Topic: ICT (তথ্য ও যোগাযোগ প্রযুক্তি), Subject: Computer and ICT (তথ্য ও যোগাযোগ প্রযুক্তি)

Best Answer Explained in Below-:

When connecting the COM (serial) port of a host computer to the COM port of a router or switch, the appropriate cable to use is a "rolled" cable, also known as a rollover cable. This cable type has wiring that is reversed at each end, meaning the pin connections are flipped – pin 1 connects to pin 8, pin 2 to pin 7, and so on. This design is specifically suited for connecting terminal devices to network equipment like routers or switches, allowing for proper communication via the serial ports.

In contrast, a crossover cable is typically used for Ethernet connections to link two similar devices directly, while a straight-through cable is used for connecting dissimilar devices like a computer to a switch. Shielded twisted pair (STP) refers to a type of cabling used for Ethernet connections that protects against interference. Thus, for the purpose of connecting a host's COM port to that of a router or switch, a rolled cable is essential to ensure correct data transmission, making it the correct answer in this scenario.