Question

a printer is behaving erratically; you suspect a faulty parallel port. which tool can you use to test the parallel port?
ammeter
cable tester
loopback plug
multimeter

Explanation:

An ammeter measures electric current, a cable tester checks cables, and a multimeter measures electrical properties like voltage, current, and resistance. A loopback plug is used to test ports by sending data out and then checking if it comes back correctly, which is suitable for testing a parallel port.

Answer:

Loopback plug